#include <fstream>
#include <queue>

using namespace std;

const int N = 2e5;

int main() {
    ifstream in("apm.in");
    ofstream out("apm.out");
    int n, m;
    in >> n >> m;
    vector <vector<pair<int, int>>> a(n + 1);
    priority_queue<pair<int, int>, vector <pair <int, int>>, greater<pair<int, int>>> pq;
    for (int i = 0; i < m; i++) {
        int x, y, c;
        in >> x >> y >> c;
        a[x].push_back({c, y});
        a[y].push_back({c, x});
    }
    in.close();
    vector <int> d(n + 1, INT_MAX);
    vector <int> leg_t(n + 1, -1);
    vector <pair<int, int>> muchii;
    vector <bool> in_t(n + 1, false);
    d[1] = leg_t[1] = 0;
    pq.push({0, 1});
    int cost_total = 0;
    while (muchii.size() < n) {
        int x = pq.top().second;
        int c = pq.top().first;
        pq.pop();
        if (!in_t[x]) {
            in_t[x] = true;
            muchii.push_back({x, leg_t[x]});
            cost_total += c;
            for (auto p: a[x]) {
                int y = p.second;
                int c = p.first;
                if (!in_t[y] && c < d[y]) {
                    d[y] = c;
                    leg_t[y] = x;
                    pq.push({d[y], y});
                }
            }
        }
    }
    out << cost_total << '\n';
    out << n - 1 << '\n';
    for (int i = 2; i <= n; i++) {
        out << i << " " << leg_t[i] << '\n';
    }
    out.close();
    return 0;
}