#include <iostream>
#include <fstream>
#include <bits/stdc++.h>
#include <vector>
#include <queue>

using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
int t[200010], n, m, cost;
vector < pair<int,int> > a[200010], rez;
priority_queue< pair<int, pair<int,int> >, vector<pair<int, pair<int,int> > >, greater<pair<int, pair<int,int> > > >pq;
pair< int, pair<int,int> >x;

int main()
{
    int i, j, k;
    fin>>n>>m;
    for(k=1; k<=m; k++)
    {
        fin>>i>>j>>cost;
        a[i].push_back({cost,j});
        a[j].push_back({cost,i});
    }
    for(auto it:a[1])
    {
        pq.push( {it.first, {1, it.second}} );
    }
    cost=0;
    t[1]=1;
    while(pq.empty()==0)
    {
        x = pq.top();
        pq.pop();
        if( t[x.second.second]==0 )
        {
            t[x.second.second] = x.second.first;
            cost = cost + x.first;
            rez.push_back({x.second.first, x.second.second});
            for(auto it: a[x.second.second])
            {

                    pq.push( {it.first, {x.second.second, it.second}} );
            }
        }
    }
    t[1]=0;
    fout<<cost<<'\n';
    fout<<n-1<<'\n';
    for(auto it: rez)
        fout<<it.first<<" "<<it.second<<'\n';

    fin.close();
    fout.close();
    return 0;
}