#include <fstream>
#include <vector>
#include <queue>
#define INF 2000000001
using namespace std;
ifstream fi("apm.in");
ofstream fo("apm.out");
int n,m;
vector <pair <int, int> > A[200001];
vector <pair <int,int> > :: iterator it;
int KEY[200001];
int P[200001];
priority_queue <pair <int, int> > Q;
int nrm;
int VIZ[200001];

int main()
{
    fi>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x,y,c;
        fi>>x>>y>>c;
        A[x].push_back({y,c});
        A[y].push_back({x,c});
    }
    KEY[1]=0;
    P[1]=0;
    for(int i=2; i<=n; i++)
    {
        KEY[i]=INF;
        P[i]=0;
    }
    for (int i=1;i<=n;i++)
        Q.push({-KEY[i],i});
    nrm=0;
    while (1)
    {
        if (nrm==n-1)
            break;
        if (Q.empty())
            break;
        pair <int, int> curent;
        curent=Q.top();
        Q.pop();
        int v;
        v=curent.second;
        if(VIZ[v]==1)
            continue;
        VIZ[v]=1;
        nrm++;
        for (it=A[v].begin();it!=A[v].end();it++)
        {
            pair <int, int> pereche;
            pereche=(*it);
            int varf=pereche.first;
            int pondere=pereche.second;
            if (pondere<KEY[varf] && VIZ[varf]==0)
            {
                KEY[varf]=pondere;
                P[varf]=v;
                Q.push({-pondere,varf});
            }
        }
    }
    int suma;
    suma=0;
    for (int i=1;i<=n;i++)
        suma=suma+KEY[i];
    fo<<suma<<"\n";
    fo<<n-1<<"\n";
    for (int i=2;i<=n;i++)
        fo<<P[i]<<" "<<i<<"\n";
    fi.close();
    fo.close();
    return 0;
}