#include <iostream>
#include <list>
#include <queue>
#include <vector>
#include <stack>
#include <fstream>
#include <map>
#include <set>
#include <algorithm>
#include <climits>
#include <cstring>

#define INF ((1 << 30) - 1)
// 2^30-1 ca sa nu fie overflow daca faci INF + INF

const int nMax = 105;

using namespace std;

class DisjointSet {
private:
    int m_parinte[nMax] = {}, m_dimensiune[nMax] = {};

public:
    explicit DisjointSet(int n) {
        for (int i = 1; i <= n; i++) {
            m_parinte[i] = i;
            m_dimensiune[i] = 1;
        }
    }

    int cauta(int x) {
        while (x != m_parinte[x]) {
            x = m_parinte[x];
        }
        return x;
    }

    void uneste(int x, int y) {
        int parinteX = cauta(x), parinteY = cauta(y);

        // Uneste arborele mai mic la arborele mai mare, pentru o complexitate mai buna
        if (m_dimensiune[parinteX] >= m_dimensiune[parinteY]) {
            m_parinte[parinteY] = parinteX;
            m_dimensiune[parinteX] += m_dimensiune[parinteY];
        } else {
            m_parinte[parinteX] = parinteY;
            m_dimensiune[parinteY] += m_dimensiune[parinteX];
        }
    }
};

class Graf {
private:
    int m_n, m_m;
    vector<int> m_listaAd[nMax];
    vector<pair<int, int>> m_ponderatListaAd[nMax];
    int m_ponderatMatrice[105][105] = {};
    vector<vector<int>> m_listaMuchii;
    vector<pair<int, pair<int, int>>> m_listaMuchiiPonderat;

    // DFS - https://www.infoarena.ro/problema/dfs
    static constexpr int dfsMax = 1;
    bool m_dfsViz[dfsMax] = {};

    // BFS - https://www.infoarena.ro/problema/bfs
    static constexpr int bfsMax = 1;
    int m_bfsDist[bfsMax] = {};
    queue<int> m_bfsQueue;

    // CTC - https://www.infoarena.ro/problema/ctc
    static constexpr int ctcMax = 1;
    int m_ctcId[ctcMax] = {}, m_ctcLow[ctcMax] = {}, m_ctcUltId = 0;
    bool m_ctcPeStiva[ctcMax] = {};
    list<list<int>> m_ctc;
    stack<int> m_ctcStack;

    // Componente biconexe - https://www.infoarena.ro/problema/biconex
    static constexpr int biconexMax = 1;
    list<list<int>> m_biconexComps;
    stack<int> m_biconexStack;
    int m_biconexLow[biconexMax] = {};

    // Muchii critice - https://leetcode.com/problems/critical-connections-in-a-network/
    static constexpr int criticeMax = 1;
    map<pair<int, int>, bool> m_criticeToRemove;
    vector<vector<int>> m_critice;
    int m_criticeLow[criticeMax] = {}; // Id-ul nodului minim in care te poti intoarce din nodul i

    // Arbore partial de cost minim - https://www.infoarena.ro/problema/apm
    int m_apcmCost = 0;
    vector<pair<int, int>> m_apcmResult;

    // Bellman-Ford - https://infoarena.ro/problema/bellmanford
    static constexpr int bellmanMax = 1;
    vector<int> m_bellmanDist = vector<int>(bellmanMax, INT_MAX);
    int m_bellmanPuneriInCoada[bellmanMax] = {}, m_bellmanInQueue[bellmanMax] = {};
    queue<int> m_bellmanQueue;
    bool m_bellmanCircuitCostNegativ = false;

    // Dijkstra - https://infoarena.ro/problema/dijkstra
    static constexpr int dijkstraMax = 1;
    vector<int> m_dijkstraDist = vector<int>(dijkstraMax, INT_MAX);
    set<pair<int, int>> m_dijkstraMinHeap; // "min".. doar e un ordered set (crescator)

    // Diametru arbore - https://www.infoarena.ro/problema/darb
    static constexpr int diametruVizMax = 1;
    bool m_diametruViz[diametruVizMax] = {};
    int m_diametruNodMax = 0, m_diametruDistMax = 0;

    // RoyFloyd - https://www.infoarena.ro/problema/royfloyd
    static constexpr int royFloydMax = 1;
    int m_royFloydDists[royFloydMax][royFloydMax] = {};

    // Flux maxim - https://infoarena.ro/problema/maxflow
    static constexpr int fluxMaximMax = 1;
    int m_fluxMaximCapacitate[fluxMaximMax][fluxMaximMax] = {}, m_fluxMaximFlux[fluxMaximMax][fluxMaximMax] = {},
            m_fluxMaximParinti[fluxMaximMax] = {};
    queue<int> m_fluxMaximQueue;


    // ---------------- Functii private ----------------
    void orientatCtcDFS(int x) {
        m_ctcStack.push(x);
        m_ctcPeStiva[x] = true;
        m_ctcId[x] = m_ctcLow[x] = ++m_ctcUltId;

        for (auto y: m_listaAd[x]) {
            // Nu am explorat nodul pana acum (neavand vreun id)
            if (m_ctcId[y] == 0) {
                orientatCtcDFS(y);
            }

            // Am intalnit un nod care inca nu a fost atribuit unei componente conexe.
            // Poate nodul curent face parte din viitoarea componenta conexa, a carei (posibila) sursa
            // a fost gasita de y.
            if (m_ctcPeStiva[y]) {
                m_ctcLow[x] = min(m_ctcLow[x], m_ctcLow[y]);
            }
        }

        // Am ajuns la nodul de start al ctc-ului explorat in prezent
        if (m_ctcId[x] == m_ctcLow[x]) {
            list<int> compCurr;
            while (true) {
                auto y = m_ctcStack.top();
                m_ctcStack.pop();

                m_ctcPeStiva[y] = false;
                compCurr.push_back(y);

                if (y == x) break;
            }
            m_ctc.push_back(compCurr);
        }
    }

    void neorientatBiconexAdd(int x, int y) {
        // Creeaza o noua componenta pentru afisare
        list<int> comp;

        // Adauga in componenta toate nodurile pana la y, inclusiv y
        while (m_biconexStack.top() != y) {
            comp.push_back(m_biconexStack.top());
            m_biconexStack.pop();
        }
        comp.push_back(y);
        m_biconexStack.pop();

        // Adauga in componenta si pe x, separat (in caz ca e un gap in stack intre y si x)
        // ^ gap-ul poate aparea daca intalnim mai multe componente biconexe ce se intorc in acelasi nod
        comp.push_back(x);

        m_biconexComps.push_back(comp);
    }

    void neorientatBiconexDfs(int x, int prev, int id) {
        // Initializam low-ul (nodul cel mai de sus din parcurgerea DFS in care putem ajunge)
        // si punem nodul curent pe stack
        m_biconexLow[x] = id;
        m_biconexStack.push(x);

        for (auto y: m_listaAd[x]) {
            // Ignoram cazul in care ne intoarcem din nodul in care am plecat
            if (y == prev) continue;

            // Nodul y nu a fost vizitat => viziteaza-l
            if (!m_biconexLow[y]) {
                // Viziteaza-l si actualizeaza low
                neorientatBiconexDfs(y, x, id + 1);
                m_biconexLow[x] = min(m_biconexLow[x], m_biconexLow[y]);

                // Am ajuns la originea ciclului / am dat peste un nod de mai jos din parcurgerea
                // DFS la care nu mai putem ajunge altfel (=> componenta biconexa)
                if (m_biconexLow[y] >= id) {
                    neorientatBiconexAdd(x, y);
                }
            }
                // Nodul y a fost vizitat => doar actualizeaza min-ul in caz ca e nevoie,
                // fara sa risti sa afisezi o componenta biconexa de doua ori
            else {
                m_biconexLow[x] = min(m_biconexLow[x], m_biconexLow[y]);
            }
        }
    }

    void neorientatMuchiiCriticeDfs(int x, int prev, int id) {
        m_criticeLow[x] = id;

        for (auto y: m_listaAd[x]) {
            // Nu te intoarce in nodul din care ai plecat
            if (y == prev) continue;

            // Ruleaza DFS in continuare, cu un id mai mare
            if (m_criticeLow[y] == 0) neorientatMuchiiCriticeDfs(y, x, id + 1);

            // Nodul vizitat din cel curent face parte dintr-un ciclu,
            // asa ca trebuie sa excludem muchia x-y
            if (m_criticeLow[y] < id + 1) {
                m_criticeToRemove[{x, y}] = m_criticeToRemove[{y, x}] = true;
            }

            // Actualizeaza low-ul nodului curent
            m_criticeLow[x] = min(m_criticeLow[x], m_criticeLow[y]);
        }
    }

    void diametruDFS(int x, int dist) {
        if (dist > m_diametruDistMax) {
            m_diametruDistMax = dist;
            m_diametruNodMax = x;
        }
        m_diametruViz[x] = 1;
        for (auto &y: m_listaAd[x]) {
            if (!m_diametruViz[y]) {
                diametruDFS(y, dist + 1);
            }
        }
    }

    void orientatRoyFloydSetup() {
        for (int i = 1; i <= m_n; i++) {
            for (int j = 1; j <= m_n; j++) {
                if (i == j) {
                    m_royFloydDists[i][j] = 0;
                } else if (m_ponderatMatrice[i][j] == 0) {
                    m_royFloydDists[i][j] = INF;
                } else {
                    m_royFloydDists[i][j] = m_ponderatMatrice[i][j];
                }
            }
        }
    }

public:
    // ---------------- Interfata publica ----------------
    explicit Graf(int n = 0, int m = 0) : m_n(n), m_m(m) {}


    /*************** Algoritmi generali ***************/
    void ponderatCitesteListaMuchii(ifstream &in) {
        for (int i = 0; i < m_m; i++) {
            int x, y, c;
            in >> x >> y >> c;
            m_listaMuchiiPonderat.push_back({c, {x, y}});
        }
    }

    void DFS(int k) {
        m_dfsViz[k] = true;

        for (auto x: m_listaAd[k]) {
            if (!m_dfsViz[x]) {
                DFS(x);
            }
        }
    }

    const auto &BFS(int start) {
        m_bfsQueue.push(start);
        m_bfsDist[start] = 1;

        while (!m_bfsQueue.empty()) {
            int curr = m_bfsQueue.front();
            m_bfsQueue.pop();

            for (auto i: m_listaAd[curr]) {
                if (m_bfsDist[i] == 0) {
                    m_bfsDist[i] = m_bfsDist[curr] + 1;
                    m_bfsQueue.push(i);
                }
            }
        }
        return m_bfsDist;
    }

    static bool potiConstruiGraf(vector<int> grade) {
        // Algoritmul Havel-Hakimi
        while (true) {
            sort(grade.begin(), grade.end(), greater<int>());

            if (grade[0] == 0) break;
            if (grade[0] > grade.size() - 1) return false;

            int maxVal = grade[0];
            for (int i = 1; i <= maxVal; i++) {
                grade[0]--;
                grade[i]--;
                if (grade[i] < 0) return false;
            }
        }

        return true;
    }

    void construiesteApcm() {
        // Algoritmul lui Kruskal: luam muchiile cu cel mai mic cost, cat timp nu
        // se creeaza cicluri.
        sort(m_listaMuchiiPonderat.begin(), m_listaMuchiiPonderat.end());

        // Foloseste un disjoint set pentru a sti daca muchia de la x la y va crea
        // un ciclu (valoarea fiecarui nod reprezentand componenta conexa din care
        // face parte).
        DisjointSet ds(m_n);

        for (auto &m: m_listaMuchiiPonderat) {
            int c = m.first, x = m.second.first, y = m.second.second;
            if (ds.cauta(x) != ds.cauta(y)) {
                ds.uneste(x, y);

                // Adauga la rezultat muchia gasita
                m_apcmCost += c;
                m_apcmResult.push_back({x, y});
            }
        }
    }

    const auto &getApcmResult() {
        return m_apcmResult;
    }

    auto getApcmCost() {
        return m_apcmCost;
    }

    /*************** Grafuri neorientate ***************/
    void neorientatCitesteListaMuchii(ifstream &in) {
        for (int i = 0; i < m_m; i++) {
            int x, y;
            in >> x >> y;
            m_listaMuchii.push_back({x, y});
        }
    }

    void neorientatListaMuchiiToListaAdiacenta() {
        for (auto &e: m_listaMuchii) {
            m_listaAd[e[0]].push_back(e[1]);
            m_listaAd[e[1]].push_back(e[0]);
        }
    }

    void neorientatCitesteListaAdiacenta(ifstream &in) {
        for (int i = 0; i < m_m; i++) {
            int x, y;
            in >> x >> y;
            m_listaAd[x].push_back(y);
            m_listaAd[y].push_back(x);
        }
    }

    int neorientatNrCompConexe() {
        int nrComp = 0;
        for (int i = 1; i <= m_n; i++) {
            if (!m_dfsViz[i]) {
                nrComp++;
                DFS(i);
            }
        }
        return nrComp;
    }

    const auto &neorientatBiconexe() {
        for (int i = 1; i <= m_n; i++) {
            if (!m_biconexLow[i]) {
                neorientatBiconexDfs(i, -1, 1);
            }
        }
        return m_biconexComps;
    }

    const auto &neorientatMuchiiCritice() {
        neorientatMuchiiCriticeDfs(0, -1, 1);

        // In rezultat, punem muchiile ce nu au fost marcate ca trebuind sa fie sterse
        for (auto &e: m_listaMuchii) {
            if (!m_criticeToRemove[{e[0], e[1]}]) {
                m_critice.push_back(e);
            }
        }

        return m_critice;
    }

    int diametru() {
        diametruDFS(1, 1);
        m_diametruDistMax = 0;
        memset(m_diametruViz, 0, sizeof(m_diametruViz));
        diametruDFS(m_diametruNodMax, 1);

        return m_diametruDistMax;
    }


    /*************** Grafuri orientate ***************/
    void orientatCitesteListaAdiacenta(ifstream &in) {
        for (int i = 0; i < m_m; i++) {
            int x, y;
            in >> x >> y;
            m_listaAd[x].push_back(y);
        }
    }

    void orientatPonderatCitesteListaAdiacenta(ifstream &in) {
        for (int i = 0; i < m_m; i++) {
            int x, y, c;
            in >> x >> y >> c;
            m_ponderatListaAd[x].push_back({y, c});
        }
    }

    void orientatPonderatCitesteMatricePonderi(ifstream &in) {
        for (int i = 1; i <= m_n; i++) {
            for (int j = 1; j <= m_n; j++) {
                int p;
                in >> p;
                m_ponderatMatrice[i][j] = p;
            }
        }
    }

    const auto &orientatCtc() {
        // Algoritmul lui Tarjan
        for (int i = 1; i <= m_n; i++) {
            // Nu am explorat nodul pana acum (neavand vreun id)
            if (m_ctcId[i] == 0) {
                orientatCtcDFS(i);
            }
        }
        return m_ctc;
    }

    void orientatRuleazaBellmanFord(int start) {
        // Gaseste graful de costuri minime, plecand din start la celelalte n-1 noduri.
        // Putem avea circuit de cost negativ -> va fi detectat.

        // Incepem cu optimizarile plecand din nodul de start
        m_bellmanQueue.push(start);
        m_bellmanDist[start] = 0;
        m_bellmanInQueue[start] = true;
        m_bellmanPuneriInCoada[start] = 1;

        // Ne oprim cand nu mai avem nimic de optimizat / am gasit un circuit cu cost negativ
        while (!m_bellmanQueue.empty() && !m_bellmanCircuitCostNegativ) {
            int x = m_bellmanQueue.front();
            m_bellmanQueue.pop();

            // Marcam nodul curent ca ne mai fiind in queue
            m_bellmanInQueue[x] = false;

            // Luam toate arcele la rand si incercam sa optimizam distante, folosindu-le
            for (auto &e: m_ponderatListaAd[x]) {
                int y = e.first, c = e.second;

                // Am gasit un arc (de la x la y) ce optimizeaza costul lui y (= obtinem
                // o distanta mai mica din start->y daca mergem prin x)
                if (m_bellmanDist[y] > m_bellmanDist[x] + c) {
                    m_bellmanDist[y] = m_bellmanDist[x] + c;

                    // Daca y nu e deja in coada, pune-l (facem verificarea ca sa nu
                    // il adaugam de mai multe ori in coada), pentru ca, optimizand
                    // distanta pana la el, putem optimiza distante si plecand din el.
                    if (!m_bellmanInQueue[y]) {
                        m_bellmanQueue.push(y);
                        m_bellmanInQueue[y] = true;

                        // Numara de cate ori au fost puse in coada nodurile. Daca un nod
                        // a fost pus de >= n ori (=> n optimizari), inseamna ca am gasit
                        // un circuit de cost negativ.
                        m_bellmanPuneriInCoada[y]++;
                        if (m_bellmanPuneriInCoada[y] >= m_n) {
                            m_bellmanCircuitCostNegativ = true;
                        }
                    }
                }
            }
        }
    }

    bool circuitNegativBellmanFord() {
        return m_bellmanCircuitCostNegativ;
    }

    const auto &getBellmanFordDists() {
        return m_bellmanDist;
    }

    const auto &orientatRuleazaDijkstra(int start) {
        // Incepem algoritmul din nodul de start
        m_dijkstraDist[start] = 0;
        // Punem in set perechea {0, [nod start]}, 0 fiind distanta de la start pana la el insusi
        m_dijkstraMinHeap.insert({0, start});

        while (!m_dijkstraMinHeap.empty()) {
            // Procesam nodul de la distanta cea mai mica fata de start
            auto x = m_dijkstraMinHeap.begin()->second;
            m_dijkstraMinHeap.erase(m_dijkstraMinHeap.begin());

            for (auto &e: m_ponderatListaAd[x]) {
                auto y = e.first, c = e.second;

                // Obtinem un drum mai scurt (fata de cel gasit) daca trecem prin x
                if (m_dijkstraDist[y] > m_dijkstraDist[x] + c) {
                    // Nodul y e deja marcat ca trebuind sa fie procesat => il scoatem din set, ca sa il readaugam
                    // cu noua distanta, mai mica (ca sa nu pierdem timp incercand sa-l optimizam cu distanta veche
                    // mai tarziu) -- 90p->100p
                    if (m_dijkstraMinHeap.count({m_dijkstraDist[y], y}) > 0) {
                        m_dijkstraMinHeap.erase(m_dijkstraMinHeap.find({m_dijkstraDist[y], y}));
                    }

                    // Actualizam distanta lui y si il punem la procesat
                    m_dijkstraDist[y] = m_dijkstraDist[x] + c;
                    m_dijkstraMinHeap.insert({m_dijkstraDist[y], y});
                }
            }
        }

        return m_dijkstraDist;
    }

    void orientatRoyFloyd() {
        orientatRoyFloydSetup();

        // Nodul k = nodul pe care incercam sa il integram in drumul de la i la j
        for (int k = 1; k <= m_n; k++) {
            // Verificam toate drumurile daca pot fi scurtate folosind k drept nod intermediar
            // (i -> ... -> k -> ... -> j)
            for (int i = 1; i <= m_n; i++) {
                for (int j = 1; j <= m_n; j++) {
                    if (m_royFloydDists[i][k] + m_royFloydDists[k][j] < m_royFloydDists[i][j]) {
                        m_royFloydDists[i][j] = m_royFloydDists[i][k] + m_royFloydDists[k][j];
                    }
                }
            }
        }
    }

    const auto &orientatRoyFloydGetDists() {
        return m_royFloydDists;
    }

    void citesteInputFluxMaxim(ifstream &in) {
        for (int i = 0; i < m_m; i++) {
            int x, y, c;
            in >> x >> y >> c;
            m_fluxMaximCapacitate[x][y] = c;
            m_listaAd[x].push_back(y);
            m_listaAd[y].push_back(x);
        }
    }

    int orientatFluxMaximBFS(int start = 1) {
        memset(m_fluxMaximParinti, 0, sizeof(m_fluxMaximParinti));

        m_fluxMaximQueue.push(start);
        m_fluxMaximParinti[start] = -1;

        while (!m_fluxMaximQueue.empty()) {
            int x = m_fluxMaximQueue.front();
            m_fluxMaximQueue.pop();

            // Din moment ce am facut graful unul neorientat (pentru a avea acces la vecinii nodului destinatie),
            // am putea sa ne intoarcem din nodul final in alte noduri inca nevizitate, dar nu vrem asta
            if (x == m_n) {
                continue;
            }

            for (auto &y: m_listaAd[x]) {
                // Daca nu am vizitat nodul y in BFS-ul curent si daca inca mai putem pompa
                // flux prin lantul x-y, viziteaza-l
                if (!m_fluxMaximParinti[y] && m_fluxMaximCapacitate[x][y] - m_fluxMaximFlux[x][y] > 0) {
                    m_fluxMaximQueue.push(y);
                    m_fluxMaximParinti[y] = x;
                }
            }
        }

        // Returnam daca am ajuns la destinatie cu parcurgerea curenta
        return m_fluxMaximParinti[m_n];
    }

    int orientatFluxMaxim() {
        // Algoritmul Edmonds-Karp

        int fluxMaximTotal = 0;

        while (orientatFluxMaximBFS()) {
            // Am creat arborele BFS -> ne intoarcem pe fiecare ruta posibila, folosindu-ne de vecinii
            // nodului final
            for (auto &x: m_listaAd[m_n]) {
                if (!m_fluxMaximParinti[x] || m_fluxMaximCapacitate[x][m_n] - m_fluxMaximFlux[x][m_n] == 0) {
                    continue;
                }

                m_fluxMaximParinti[m_n] = x;

                // Gaseste fluxul minim ce poate fi pompat pe lantul gasit de BFS
                int fluxMinimLant = INT_MAX, curr = m_n;
                while (m_fluxMaximParinti[curr] != -1) {
                    int prev = m_fluxMaximParinti[curr];
                    fluxMinimLant = min(fluxMinimLant, m_fluxMaximCapacitate[prev][curr] - m_fluxMaximFlux[prev][curr]);
                    curr = prev;
                }
                if (fluxMinimLant == 0) {
                    continue;
                }

                // Actualizeaza fluxurile
                curr = m_n;
                while (m_fluxMaximParinti[curr] != -1) {
                    int prev = m_fluxMaximParinti[curr];
                    m_fluxMaximFlux[prev][curr] += fluxMinimLant;
                    m_fluxMaximFlux[curr][prev] -= fluxMinimLant;
                    curr = prev;
                }

                fluxMaximTotal += fluxMinimLant;
            }
        }

        return fluxMaximTotal;
    }

    static const int hamiltonMinimMax = 19;
    int m_hamiltonMinimDP[1 << hamiltonMinimMax][hamiltonMinimMax] = {};

    void citesteInputCicluHamiltonian(ifstream &in) {
        for (int i = 0; i < m_m; i++) {
            int x, y, c;
            in >> x >> y >> c;
            m_ponderatListaAd[y].push_back({x, c});
        }
    }

    int orientatCostMinimCicluHamiltonian() {
        for (int k = 0; k < 1 << hamiltonMinimMax; k++) {
            for (int i = 0; i < m_n; i++) {
                m_hamiltonMinimDP[k][i] = INF;
            }
        }
        m_hamiltonMinimDP[1][0] = 0;

        for (int k = 0; k <= 1 << (m_n + 1); k++) {
            for (int i = 0; i < m_n; i++) {
                if (k & (1 << i)) {
                    for (auto &pairJ: m_ponderatListaAd[i]) {
                        int j = pairJ.first, c = pairJ.second;
                        if (k & (1 << j)) {
                            m_hamiltonMinimDP[k][i] = min(
                                    m_hamiltonMinimDP[k][i],
                                    m_hamiltonMinimDP[k & ~(1 << i)][j] + c
                            );
                        }
                    }
                }
            }
        }

        int res = INF;
        for (auto &pair0: m_ponderatListaAd[0]) {
            int i = pair0.first, c = pair0.second;
            res = min(res, m_hamiltonMinimDP[((1 << m_n) - 1)][i] + c);
        }

        return (res != INF) ? res : -1;
    }
};

int main() {
    // Input rapid
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    // I/O
    ifstream in("hamilton.in");
    ofstream out("hamilton.out");

    int n, m;
    in >> n >> m;

    Graf g(n, m);
    g.citesteInputCicluHamiltonian(in);
    in.close();

    int costMinim = g.orientatCostMinimCicluHamiltonian();
    if (costMinim < 0) out << "Nu exista solutie";
    else out << costMinim;

    out.close();
    return 0;
}