#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
int n,m,ind[400001],dis[400001],x[400001],y[400001],cost[400001],sum=0;
vector <int> arbore;

int root(int a){
    if(dis[a]!=a)
        dis[a]=root(dis[a]);

    return dis[a];
}


void reunim(int a,int b)
{
    dis[root(a)]=root(b);
}

int Cmp(int i,int j)
{

    return (cost[i]<cost[j]);
}

int main()
{
    f>>n >>m;
    for(int i=1;i<=m;i++){
        f>>x[i] >>y[i] >> cost[i];
        ind[i]=i;
    }

    sort(ind+1,ind+m+1,Cmp);
    for(int i=1;i<=n;i++) dis[i]=i;

    for(int i=1;i<=m;i++)
    {
        if(root(dis[x[ind[i]]])!=root(dis[y[ind[i]]])){

            reunim(x[ind[i]],y[ind[i]]);
            sum+=cost[ind[i]];
            arbore.push_back(ind[i]);
        }

    }
    g << sum << "\n";
    g << n-1 << "\n";

    for(int i=0;i<arbore.size();i++)
        g << x[arbore[i]] << " " << y[arbore[i]] << "\n";

    return 0;
}