#include <bits/stdc++.h>
#define NMAX 200000
#define MMAX 400000

using namespace std;

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

struct muchie {
    int a, b, cost;
}mch[MMAX + 2];

int n, m;
int cnt, cost_min;
int rad[NMAX + 2], rang[NMAX + 2];
vector<pair<int, int>> mch_apm;

bool cmp(muchie a, muchie b) {
    return a.cost < b.cost;
}

int Find(int x) {
    if (x == rad[x]) {
        return x;
    }
    return rad[x] = Find(rad[x]);
}

void Union(int x, int y) {
    if (rang[x] < rang[y]) {
        rad[x] = y;
    }
    else {
        if (rang[x] == rang[y]) {
            rang[x]++;
        }
        rad[y] = x;
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    fin.tie(NULL);
    fout.tie(NULL);

    fin >> n >> m;
    for (int i = 1; i <= n; i++) {
        rad[i] = i;
        rang[i] = 1;
    }
    for (int i = 1; i <= m; i++) {
        fin >> mch[i].a >> mch[i].b >> mch[i].cost;
    }

    sort(mch + 1, mch + m + 1, cmp);

    for (int i = 1; i <= m; i++) {
        int rad_a = Find(mch[i].a);
        int rad_b = Find(mch[i].b);
        if (rad_a != rad_b) {
            cost_min += mch[i].cost;
            mch_apm.push_back({mch[i].a, mch[i].b});
            Union(rad_a, rad_b);
            cnt++;
            if (cnt == n - 1) {
                break;
            }
        }
    }

    fout << cost_min << '\n';
    fout << cnt << '\n';
    for (int i = 0; i < cnt; i++) {
        fout << mch_apm[i].first << ' ' << mch_apm[i].second << '\n';
    }
    return 0;
}