#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <bitset>

using namespace std;

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

const int N = 2e5;
const int INF = 1e9;

int n, m, cost;
bitset<N + 5> apm;
vector<int> dist(N + 5, INF);
vector<pair<int, int>> adj[N + 5], ans, father(N + 5);
priority_queue<pair<int, int>> pq;

int main() {
    in >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y, c;
        in >> x >> y >> c;
        adj[x].emplace_back(y, c);
        adj[y].emplace_back(x, c);
    }
    dist[1] = 0;
    pq.emplace(0, 1);
    while (!pq.empty()) {
        int node = pq.top().second;
        pq.pop();
        if (apm[node])
            continue;
        apm[node] = true;
        if(father[node].first != 0) {
            cost += father[node].second;
            ans.emplace_back(father[node].first, node);
        }
        for (auto it: adj[node]) {
            if (!apm[it.first] && dist[it.first] > it.second) {
                dist[it.first] = it.second;
                father[it.first] = make_pair(node, it.second);
                pq.emplace(-dist[it.first], it.first);
            }
        }
    }
    out << cost << '\n' << ans.size() << '\n';
    for (auto it: ans)
        out << it.first << ' ' << it.second << '\n';
    return 0;
}