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

using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");

const int NMAX=100005;
vector<pair<int, int>> G[NMAX];
bitset<NMAX> viz;
priority_queue<tuple<int, int, int>> pq;
int n, m, s=0, cost, nod, k;
pair<int, int> sol[NMAX];

void citire()
{
    fin>>n>>m;
    for(int i=1; i<=m; ++i)
    {
        int x, y, c;
        fin>>x>>y>>c;
        G[x].push_back(make_pair(y, c));
        G[y].push_back(make_pair(x, c));
    }
}

void apm(int start)
{
    pq.push(make_tuple(0, start, 0));
    while(!pq.empty())
    {
        int nod=get<1>(pq.top());
        int nod2=get<2>(pq.top());
        int cost=-get<0>(pq.top());
        pq.pop();
        if(!viz[nod])
        {
            viz[nod]=1;
            s+=cost;
            k++;
            sol[k]=make_pair(nod, nod2);
            for(auto i: G[nod])
            {
                int vecin=i.first;
                int costv=i.second;
                if(!viz[vecin])
                    pq.push(make_tuple(-costv, vecin, nod));
            }
        }
    }
}
int main()
{
    citire();
    apm(1);
    fout<<s<<endl<<k-1<<endl;
    for(int i=2; i<=k; ++i)
        fout<<sol[i].first<<" "<<sol[i].second<<endl;
}