#include <bits/stdc++.h>

using namespace std;

const int NMAX = 2e5;
const int INF = 1e9;
vector<pair<int, int>> G[NMAX + 1];
int d[NMAX + 1], vis[NMAX + 1];
int p[NMAX + 1];

vector<pair<int, int>> prim(int n, int m, ifstream &f) {
    for (int i = 1; i <= m; i++) {
        int x, y, c;
        f >> x >> y >> c;
        G[x].push_back({y, c});
        G[y].push_back({x, c});
    }
    for (int i = 1; i <= n; i++) {
        d[i] = INF;
    }
    int apm = 0;
    d[1] = 0;

    set<pair<int, int>> s;
    s.insert({d[1], 1});
    while (s.size() > 0) {
        auto it = s.begin();
        int minim = (*it).first;
        int node = (*it).second;
        s.erase(it);
        vis[node] = 1;
        apm += minim;
        for (auto it : G[node]) {
            if (!vis[it.first] && d[it.first] > it.second) {
                s.erase({d[it.first], it.first});
                d[it.first] = it.second;
                s.insert({d[it.first], it.first});
                p[it.first] = node;
            }
        }
    }

    vector<pair<int, int>> mst_edges;
    for (int i = 2; i <= n; i++) {
        mst_edges.push_back({i, p[i]});
    }
    return mst_edges;
}

int main() {
    int n, m;
    ifstream f("apm.in");
    ofstream g("apm.out");
    f >> n >> m;

    vector<pair<int, int>> mst_edges = prim(n, m, f);

    int apm = 0;
    for (const auto &edge : mst_edges) {
        for (const auto &adj : G[edge.first]) {
            if (adj.first == edge.second) {
                apm += adj.second;
                break;
            }
        }
    }

    g << apm << '\n';
    g << mst_edges.size() << '\n';
    for (const auto &e : mst_edges) {
        g << e.first << ' ' << e.second << '\n';
    }

    return 0;
}