#include <bits/stdc++.h>
using namespace std;
      
ifstream in("apm.in");
ofstream out("apm.out");

const int inf = 1e9;

int n, m;
vector< vector< pair< int, int > > > G;
vector< pair< int, int > > edges;
vector< int > minCost, tata;
vector< bool > inAPM;

void Prim() {
    minCost.resize(n, inf); inAPM.resize(n, false); tata.resize(n, -1);

    priority_queue< pair< int, int >, vector< pair< int, int > >, greater< pair< int, int > > > pq;
    pq.push({0, 0});
    minCost[0] = 0;
    inAPM[0] = true;

    while(!pq.empty()) {
        int tempNode = pq.top().second; pq.pop();
        inAPM[tempNode] = true;

        for(auto vecin: G[tempNode]) {
            if(!inAPM[vecin.first] && vecin.second < minCost[vecin.first]) {
                minCost[vecin.first] = vecin.second;
                pq.push({minCost[vecin.first], vecin.first});
                tata[vecin.first] = tempNode;
            }
        }
    }
}

int main() {
    ios::sync_with_stdio(false); in.tie(0); out.tie(0);
 
    in >> n >> m;
    
    G.resize(n);
    for(int i = 1; i <= m; ++i) {
        int x, y, cost; in >> x >> y >> cost;
        --x; --y;
        G[x].push_back({y, cost});
        G[y].push_back({x, cost});
    }

    Prim();

    int cost = 0;
    for(int i = 0; i < n; ++i) {
        if(minCost[i] != inf) {
            cost += minCost[i];
        }
    }

    out << cost << "\n";

    for(int i = 0; i < n; ++i) {
        if(tata[i] != -1) {
            edges.push_back({i + 1, tata[i] + 1});
        }
    }

    out << (int)edges.size() << "\n";
    for(auto it: edges) {
        out << it.first << " " << it.second << "\n";
    }
 
    in.close(); out.close();
      
    return 0;
}