#include<iostream>
#include<algorithm>
#include<vector>
#include<fstream>

using namespace std;

const int maxn = 400100;

int GR[maxn],X[maxn],Y[maxn],C[maxn];
int N,M,ANS,IND[maxn];
vector<int> VANS;

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

bool cmpf(int i,int j)
{
    return(C[i] < C[j]);
}
int grupa(int i)
{
    if (GR[i] == i)
    {
        return i;
    }
    GR[i] = grupa(GR[i]);
    return GR[i];
}

void reuniune(int i,int j)
{
    GR[grupa(i)] = grupa(j);
}

int main()
{
    in>>N>>M;
    for(int i = 1;i <= M; i++)
    {
        in>>X[i]>>Y[i]>>C[i];
        IND[i]=i;
    }
    for(int i = 1;i <= N; i++)
    {
        GR[i] = i;
    }
    sort(IND + 1,IND + M + 1,cmpf);
    for(int i = 1;i <= M; i++)
    {
        if (grupa(X[IND[i]]) != grupa(Y[IND[i]]))
        {
            ANS += C[IND[i]];
            reuniune(X[IND[i]],Y[IND[i]]);
            VANS.push_back(IND[i]);
        }
    }
    out<<ANS<<endl;
    out<<N-1<<endl;
    for(int i = 0;i < N - 1; i++)
        out<<X[VANS[i]]<<" "<<Y[VANS[i]]<<endl;
    return 0;
}