#include <fstream>
#include <vector>

using namespace std;
const int MAXN = 20;
const int MAXX = (1<<18)+3;
const int INF = 0x3f3f3f3f;
ifstream f("hamilton.in");
ofstream g("hamilton.out");
int N, M, Sol,x,y;
int Cost[MAXN][MAXN];
int C[MAXX][MAXN];
vector <int> A[MAXN];

int main()
{
    f >> N >> M;
    for (int i = 0; i < N; ++i)
        for (int j = 0; j < N; ++j) Cost[i][j] = INF;
    for (int i = 1; i <= M; ++i)
    {
        f >> x >> y;
        A[y].push_back(x);
        f >> Cost[x][y];
    }
    for (int i = 0; i < 1 << N; ++i)
        for (int j = 0; j < N; ++j) C[i][j] = INF;
    C[1][0] = 0;

    for (int i = 0; i < 1 << N; ++i)
        for (int j = 0; j < N; ++j)
            if (i & (1<<j))
                for (int k = 0; k < A[j].size(); ++k)
                    if (i & (1<<A[j][k]))
                        C[i][j] = min(C[i][j], C[i ^ (1<<j)][ A[j][k] ] + Cost[ A[j][k] ][j]);
    Sol = INF;
    for (int i = 0; i < A[0].size(); ++i)
        Sol = min(Sol, C[(1<<N) - 1][ A[0][i] ] + Cost[ A[0][i] ][0]);

    if (Sol == INF) g << "Nu exista solutie" << '\n';
    else g << Sol <<'\n';

    return 0;
}