#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
#define MAX 200010
#define cout fout
priority_queue <pair<int, pair<int, int> > > Q;
typedef vector <pair<int, int> > :: iterator iter;
vector <pair<int, int> > G[MAX];
int viz[MAX], dr;
pair<int, int> sol[MAX];
int main()
{
    int n, m, x, y, c, nod, s = 0;
    fin >> n >> m;
    while(m--)
    {
        fin >> x >> y >> c;
        G[x].push_back(make_pair(y, c));
        G[y].push_back(make_pair(x, c));
    }
    Q.push(make_pair(0, make_pair(0, 1)));
    while(Q.size())
    {
        pair<int, pair<int, int> > aux = Q.top();
        Q.pop();
        if(viz[aux.second.second])
            continue;
        nod = aux.second.second;
        viz[nod] = 1;
        s += aux.first;
        sol[++dr] = make_pair(aux.second.first, aux.second.second);
        for(iter it = G[nod].begin() ; it != G[nod].end() ; it++)
        {
            if(!viz[it->first])
            {
                Q.push(make_pair(-it->second, make_pair(nod, it->first)));
            }
        }
    }
    cout << -s << "\n";
    cout << n - 1 << "\n";
    int i;
    for(i = 2 ; i <= dr ; i++)
    {
        cout << sol[i].first << " " << sol[i].second << "\n";
    }
}