#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define nmax 200003
#define mmax 400003
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
int n,m, d[nmax], viz[nmax], tata[nmax], ctot;
vector <pair<int,int> > v[nmax],sol;
priority_queue< pair<int,int> > pq;
void citire()
{
    int i,x,y,c;
    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>x>>y>>c;
        v[x].push_back({y,c});
        v[y].push_back({x,c});
    }
}

void prim()
{
    int i,j, nod, cost, next, cst;

    for(i=2; i<=n; i++)
        d[i]=1e9;
    pq.push({0,1});
    while(!pq.empty())
    {
        nod=pq.top().second;
        cost=-pq.top().first;
        pq.pop();
        if(d[nod]<cost) continue;
        ctot+=cost;
        viz[nod]=1;

        if(nod!=1)
            sol.push_back({tata[nod],nod});

        for(j=0; j<v[nod].size(); j++)
        {
            next=v[nod][j].first;
            cst=v[nod][j].second;

            if(!viz[next])
            {
                if(d[next]>cst)
                {
                    d[next]=cst;
                    pq.push({-d[next],next});
                    tata[next]=nod;
                }
            }
        }
    }
}

int main()
{
    citire();
    prim();
    g<<ctot<<"\n"<<n-1<<"\n";
    int i;
    for(i=0; i<sol.size(); i++)
        g<<sol[i].first<<" "<<sol[i].second<<"\n";
    f.close();
    g.close();
    return 0;
}