#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <algorithm>
#include <limits.h>
#include <bits/stdc++.h>
#define ll long long
#define sz(x) (int)(x).size()
using namespace std;

const int N = 200005;

int n, m;
int cost[N];
vector<pair<int,int>>graf[N];
vector<pair<int,int>> ans;
bool amfost[N];

struct cmp{
    bool operator()(pair<int,pair<int,int>> a,pair<int,pair<int,int>>  b){
        return a.second.second > b.second.second;
    }
};

priority_queue<pair<int,pair<int,int>> , vector<pair<int,pair<int,int>>> , cmp> coada;

void calc(int nod, int last) {
    cost[nod] = 0; // root
    coada.push(make_pair(nod, make_pair(last, cost[nod])));

    while(coada.empty() == false) {
        last = coada.top().second.first;
        nod = coada.top().first;
        coada.pop();

        //cout << nod << " " << last << '\n';

        if(amfost[nod] == true) {
            cout << "JUCK" << '\n';
            continue;
        }

        ans.push_back(make_pair(nod, last));
        amfost[nod] = true;

        for (int i = 0; i < (int)graf[nod].size(); ++i) {

            int to = graf[nod][i].first;
            int drum = graf[nod][i].second;

            if(cost[to] > drum && amfost[to] == false){
                cost[to] = drum;
                //cout << to << " " << nod << '\n';
                coada.push(make_pair(to, make_pair(nod, cost[to])));
            }

        }
        //cout << '\n';

    }

}

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

    fin >> n >> m;

    for (int i = 1; i <= n; ++i)
        cost[i] = INT_MAX;

    int costMin = INT_MAX, nodMin;
    for (int i = 1; i <= m; ++i) {
        int a, b, c;
        fin >> a >> b >> c;
        graf[a].push_back(make_pair(b,c));
        graf[b].push_back(make_pair(a,c));

        if(costMin > c) {
            costMin = c;
            nodMin = a;
        }
    }
    calc(nodMin, 0);
    //cout << '\n';
    int sum = 0;
    for (int i = 1; i <= n; ++i) {
        sum += cost[i];
      //  cout << cost[i] << " " << i << '\n';

    }
    //cout << '\n';
    fout << sum << '\n';
    fout << (int)ans.size() - 1<< '\n';
    for (int i = 1; i < (int)ans.size(); ++i)
        fout << ans[i].first << " " << ans[i].second << '\n';

    return 0;
}