#include <fstream>
#include <set>
#include <vector>

using namespace std;

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

int n, m;
vector<vector<pair<int, int>>> adj;

int main(){
    fin>>n>>m;
    adj.resize(n+1);
    while(m--){
        int x, y, cost;
        fin>>x>>y>>cost;
        adj[x].push_back({y, cost});
        adj[y].push_back({x, cost});
    }
    set<pair<int, int>> q;
    vector<int> d(n+1, 1e9), tata(n+1, 0), viz(n+1, 0);
    d[1] = 0;
    q.insert({d[1], 1});
    while(!q.empty()){
        auto p = q.begin();
        q.erase(p);

        viz[p->second] = 1;

        for(auto &nod : adj[p->second]){
            int vf = nod.first;
            int cost = nod.second;
            if(d[vf] > cost && !viz[vf]){
                tata[vf] = p->second;
                q.erase({d[vf], vf} ); //!!!!intai stergem perechea veche
                d[vf] = cost;

                q.insert({d[vf], vf});
            }
        }
    }
    int cost = 0;
    vector<pair<int, int>> apcm;
    for(int i=1; i<=n; ++i){
        if(tata[i] != 0){
            apcm.push_back({i, tata[i]});
            cost += d[i];
        }
    }
    fout<<cost<<'\n';
    fout<<apcm.size()<<'\n';
    for(auto &e : apcm){
        fout<<e.first<<" "<<e.second<<'\n';
    }
    fout.close();
    return 0;
}