#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

ifstream fin("apm.in");
ofstream fout("apm.out");


vector<pair<int, int>> prim(vector<vector<pair<int,int>>> &la, int N, int &costTotal) {
    vector<int> d(N+1, 1e9);
    vector<int> tata(N+1, 0);
    vector<int> viz(N+1, 0);

    priority_queue<pair<int, int>, vector<pair<int,int>>, greater<pair<int,int>>> pq;

    d[1] = 0;
    pq.push({d[1], 1});
    while (!pq.empty()) {
        pair<int, int> crt = pq.top();
        pq.pop();

        if (viz[crt.second] == 1)
            continue;

        viz[crt.second] = 1;
        for (auto& vecin : la[crt.second]) {
            int cost = vecin.first;
            int nod = vecin.second;
            if (d[nod] > cost && viz[nod] == 0) {
                d[nod] = cost;
                tata[nod] = crt.second;
                pq.push({d[nod], nod});
            }
        }
    }
    
    costTotal = 0;
    vector<pair<int, int>> apcm;
    for (int i = 1; i <= N; i++) {
        if (tata[i] != 0) {
            apcm.push_back({i, tata[i]});
            costTotal += d[i];
        }
    }
    return apcm;
}

int main() {

    int N, M;
    fin >> N >> M;
    vector<vector<pair<int,int>>> la(N+1);
    for (int i = 0; i < M; i++) {
        int x, y, w;
        fin >> x >> y >> w;
        la[x].push_back({w, y});
        la[y].push_back({w, x});

    }

    int costTotal = 0;
    vector<pair<int, int>> apcm = prim(la, N, costTotal);

    fout << costTotal << endl;
    fout << apcm.size() << endl;
    for (auto& m : apcm) {
        fout << m.first << " " << m.second << endl;
    }

    return 0;
}