#include <fstream>
#include <queue>
#include <vector>
#define nmax 200001
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
vector <pair <int,int> > v[nmax];
vector <pair <int,int> > sol;
priority_queue <pair<int,pair <int,int> >,vector <pair<int,pair <int,int> > >,greater<pair< int, pair <int,int> > > > h;
int n,m,i,x,y,z,t[nmax],nod,ct;
int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y>>z;
        v[x].push_back(make_pair(z,y));
        v[y].push_back(make_pair(z,x));
    }
    h.push(make_pair(0,make_pair(1,1)));
    while(!h.empty())
    {
        nod=h.top().second.second;
        if(!t[nod])
        {
            t[nod]=h.top().second.first;
            ct+=h.top().first;
            h.pop();
            sol.push_back(make_pair(nod,t[nod]));
            for(i=0;i<v[nod].size();i++)
                if(!t[v[nod][i].second])
            {
                x=v[nod][i].second;
                h.push(make_pair(v[nod][i].first,make_pair(nod,v[nod][i].second)));
            }
        }
        else h.pop();
    }
    g<<ct<<'\n'<<n-1<<'\n';
    for(i=1;i<sol.size();i++)
        g<<sol[i].first<<' '<<sol[i].second<<'\n';
    return 0;
}