#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
using namespace std;
vector <pair<int,int> > G[200005];
vector <pair<int,int> > :: iterator it;
priority_queue <pair<int,pair<int,int> > > q;
int n,m,mapm=0,cost=0;
bool vViz[200005];
int vTati[200005];
void citire()
{
    int aux1,aux2,aux3;
    scanf("%d%d",&n,&m);
    for(int i=1; i<=m; i++)
    {
        scanf("%d%d%d",&aux1,&aux2,&aux3);
        G[aux1].push_back(make_pair(aux2,aux3));
        G[aux2].push_back(make_pair(aux1,aux3));
    }
}
void apm()
{
    int costaux,nod,tata;
    q.push(make_pair(0,make_pair(0,1)));
    vViz[0]=1;
    while(!q.empty())
    {
        costaux=-q.top().first;
        nod=q.top().second.second;
        tata=q.top().second.first;
        q.pop();

        if(!vViz[nod])
        {
            cost+=costaux;
            vTati[nod]=tata;
            vViz[nod]=1;
            //printf("%d %d\n",tata,nod);
            mapm++;
        }

        for(it=G[nod].begin(); it!=G[nod].end(); it++)
        {
            if(!vViz[it->first])
            {
                q.push(make_pair(-it->second,make_pair(nod,it->first)));
            }
        }
    }
}
int main()
{
    freopen("apm.in","r",stdin);
    freopen("apm.out","w",stdout);
    citire();
    apm();
    printf("%d\n%d\n",cost,n-1);
    for(int i=2;i<=n;i++)
        printf("%d %d\n",i,vTati[i]);
    return 0;
}