#include <bits/stdc++.h>

using namespace std;

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

set <pair <int,int> > s;
vector <pair <int,int> > v[200005];
int tot_dist,viz[200005],dist[200005],tata[200005];
int n,m,i,x,y,cost;
int oo=2000000009;



int main()
{

    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y>>cost;
        v[x].push_back({y,cost});
        v[y].push_back({x,cost});
    }
    for(int i=1; i<=n; i++)
        dist[i]=oo;
    dist[1]=0;
    s.insert({0,1}); ///dist,nod
    while(s.empty()==0)
    {
        int nod=s.begin()->second;
        int dist_nod=s.begin()->first;
        s.erase(s.begin());
        if(viz[nod]==0)
        {
            viz[nod]=1;
            tot_dist+=dist_nod;
            for(auto k:v[nod])
            {
                if(dist[k.first]>k.second && viz[k.first]==0)
                {
                    dist[k.first]=k.second;
                    s.insert({dist[k.first],k.first});
                    tata[k.first]=nod;
                }
            }
        }
    }
    fout<<tot_dist<<'\n';
    fout<<n-1<<'\n';
    for(int i=2; i<=n; i++)
        fout<<i<<" "<<tata[i]<<'\n';
    return 0;
}