#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
//determina arborele partial de cost minim
//100p
ifstream fin("apm.in");
ofstream fout("apm.out");

const int MAX = 200005, INF = (1 << 30);

int n, m;
int costNod[MAX], tata[MAX]; int costTotal = 0;
bool inArbore[MAX];

struct Compara //criteriu de ordonare crescatoare a heap-ului,
{              //in functie de costul muchiei care duce la acel nod
    bool operator() (pair < int, int > x, pair < int, int > y)
    {
        return (x.second > y.second);
    }
};

priority_queue < pair < int, int >, vector < pair < int, int > >, Compara > heap;
//heap-ul va retine indicele unui nod si distanta dintre arbore si acel nod

vector < pair < int, int > > drum[MAX];

void Citire()
{
    fin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int x, y, cost;
        fin >> x >> y >> cost;
        drum[x].push_back(make_pair(y, cost));
        drum[y].push_back(make_pair(x, cost));
    }
}

void Prim()
{
    for (int i = 2; i <= n; i++) //costul fiecarui nod (mai putin al primului) devine infinit
    {
        costNod[i] = INF;
    }
    heap.push(make_pair(1, 0)); //punem nodul de plecare in heap

    while(!heap.empty()) //cat timp heap-ul nu e gol
    {
        int nodActual = heap.top().first; //extragem nodul cel mai apropiat de graf
        heap.pop();                       //(adica cel care are muchia spre graf de cost minim)

        if (!inArbore[nodActual]) //daca nu e deja in arbore
        {
            inArbore[nodActual] = true; //il punem in arbore
            for (int i = 0; i < drum[nodActual].size(); i++) //ii parcurgem vecinii
            {
                int nodUrmator = drum[nodActual][i].first; //extragem vecinul
                int cost = drum[nodActual][i].second;

                if (!inArbore[nodUrmator]) //daca vecinul nu e in arbore
                {
                    if (cost < costNod[nodUrmator]) //si noul cost (spre arbore) e mai mic decat cel vechi
                    {
                        heap.push(make_pair(nodUrmator, cost)); //il introducem in heap
                        costNod[nodUrmator] = cost; //ii memoram noul cost
                        tata[nodUrmator] = nodActual; //si ii actualizam tatal
                    }
                }
            }

        }
    }
}

void Afisare()
{
    for (int i = 2; i <= n; i++)
    {
        costTotal += costNod[i]; //costul arborelui este suma costurilor muchiilor
    }
    fout << costTotal << '\n';
    fout << n - 1 << '\n';
    for (int i = 2; i <= n; i++) //folosim vectorul de tati pt a afisa muchiile din arbore
    {
        fout << i << ' '  << tata[i] << '\n';
    }
}

int main()
{
    Citire();
    Prim();
    Afisare();
    return 0;
}