#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
#define N_MAX 200005
int n, m, d, viz[N_MAX], s;
vector <pair<int, int> >G[N_MAX];
///                  dist      nod  tata
priority_queue <pair<int, pair<int, int> > > pq;
vector <pair <int, int> > v;
void apm()
{
    pair <int, pair <int, int> > _top;
    int nod;
    pq.push({0,{1, 0}});
    while(!pq.empty())
    {
        _top = pq.top();
        pq.pop();
        nod = _top.second.first;
        if(viz[nod])
            continue;
        viz[nod] = 1;
        s += -_top.first;
        v.push_back({_top.second.second, nod});
        for(auto it:G[nod])
            pq.push({-it.second, {it.first, nod}});
    }
}
int main()
{
    f >> n >> m;
    int x, y, z;
    for(int i = 1; i <= m; i++)
    {
        f >> x >> y >> z;
        G[x].push_back({y,z});
        G[y].push_back({x,z});
    }
    apm();
    g << s << "\n" << n - 1 << "\n";
    for(int i = 1; i < v.size(); i++)
        g << v[i].first << " " << v[i].second << "\n";
    return 0;
}