#include <cstdio>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <iomanip>
#include <fstream>

#define NMax 400005
#define mod 1999999973
#define INF 0x3f3f3f3f
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");

struct muchie{
    int x,y,c;
}M[NMax];

int n,m,nr,vf1,vf2,ANS;
int sol[NMax],rang[NMax],rad[NMax];

int cmp(muchie x, muchie y){
    return (x.c < y.c);
}
int root(int k){
    while(rad[k] != k)
        k = rad[k];
    return k;
}
int main()
{
    f >> n >> m;
    for(int i = 1; i <= m; ++i){
        f >> M[i].x >> M[i].y >> M[i].c;
    }
    for(int i = 1; i <= n; ++i){
        rad[i] = i;
        rang[i] = 1;
    }
    sort(M + 1, M + 1 + m,cmp);
    for(int i = 1; i <= m && nr <= n - 1; ++i){
        vf1 = root(M[i].x);
        vf2 = root(M[i].y);

        if(vf1 != vf2){
            ANS += M[i].c;
            sol[++nr] = i;

            if(rang[vf1] > rang[vf2]){
                rang[vf1] += rang[vf2];
                rad[vf2] = rad[vf1];
            }else{
                rang[vf2] += rang[vf2];
                rad[vf1] = rad[vf2];
            }
        }
    }
    g << ANS <<"\n";
    g << nr <<"\n";
    for(int i = 1; i <= nr; ++i){
        g << M[sol[i]].x <<" " <<M[sol[i]].y <<"\n";
    }
    return 0;
}