#include<stdio.h>
#include<algorithm>
#include<vector>
using namespace std;

FILE *f = fopen("apm.in", "r");
FILE *g = fopen("apm.out", "w");

const int maxn = 400100;

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

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);
}

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

int main()
{

    fscanf(f, "%d %d\n",&N,&M);
    for(int i = 1;i <= M;++i)
    {
        fscanf(f, "%d %d %d\n",&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]);
        }
    }
    fprintf(g, "%d\n",ANS);
    fprintf(g, "%d\n",N - 1);
    for(int i = 0;i < N - 1; ++i)
        fprintf(g, "%d %d\n",X[VANS[i]],Y[VANS[i]]);
    return 0;
}