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

using namespace std;

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

int n, m, dist[100001], viz[100001], tata[100001];
vector<pair<int, int>> gf[100001];
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
const int INF = 2e9;

void prim(int start) {
    dist[start] = 0;
    pq.push({ dist[start], start });
    viz[start] = 1;
    while (!pq.empty()) {
        int cost = pq.top().first;
        int nod = pq.top().second;
        pq.pop();
        viz[nod] = 1;
        for (auto vecin : gf[nod]) {
            int costnou = vecin.first;
            int nodnou = vecin.second;
            if (!viz[nodnou] && dist[nodnou] > costnou) {
                dist[nodnou] = costnou;
                tata[nodnou] = nod;
                pq.push({ dist[nodnou], nodnou });
            }
        }
    }
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y, c;
        fin >> x >> y >> c;
        gf[x].push_back({ c, y });
        gf[y].push_back({ c, x });
    }
    for (int i = 1; i <= n; i++)
        dist[i] = INF;
    prim(1);
    int s = 0;
    for (int i = 1; i <= n; i++)
        for (auto vecin : gf[i])
            if (vecin.second == tata[i])
                s += vecin.first;
    fout << s << "\n" << n - 1 << "\n";
    for (int i = 2; i <= n; i++)
            fout << tata[i] << " " << i << "\n";
    return 0;
}