#include <iostream>
#include <queue>
#include <vector>
#include <bitset>
#include <fstream>
using namespace std;
const int N = 1e5 + 10;
vector <pair<int,int>> v[N]; /// first cost second nod
vector <int> act;
bitset <N> viz;
int tata[N];
int main() {
    int n, m;
    ifstream f("apm.in");
    f >> n >> m;
    for(int i = 1; i <= m; i++){
        int x, y, z;
        f >> x >> y >> z;
        v[x].push_back({z, y});
        v[y].push_back({z, x});
    }
    priority_queue <pair<int, pair<int,int>>> pq; /// cost {nod incident}
    pq.push({0, {0, 1}});
    int rez = 0;
    while(!pq.empty()){
        int nod = pq.top().second.second;
        if(viz[nod]){
            pq.pop();
            continue;
        }
        tata[nod] = pq.top().second.first;
        rez += (-pq.top().first);
        viz[nod] = 1;
        pq.pop();
        for(auto vecin: v[nod]){
            pq.push({-vecin.first, {nod, vecin.second}});
        }
    }
    f.close();
    ofstream g("apm.out");
    g << rez << "\n" << n - 1 << "\n";
    for(int i = 2; i <= n; i++){
        g << i << " " << tata[i] << "\n";
    }
    return 0;
}