#include <fstream>
#include <vector>
#include <climits>
#define NMAX 200002
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
struct varf
{
    int vf, c;
};
int n;
vector <varf> G[NMAX];
int cost_apm;
int cmin[NMAX];
int prec[NMAX];
int uz[NMAX];
void citire()
{
    int i, m, x, y, cost;
    varf v;

    fin >> n >> m;

    for(i=0;i<m;i++)
    {
        fin >> x >> y >> cost;

        v.vf=y;
        v.c=cost;
        G[x].push_back(v);

        v.vf=x;
        G[y].push_back(v);
    }
}
void prim(int start)
{
    int x, i, j, minim, vfmin;
    for(x=1;x<=n;x++)
    {
        prec[x]=0;
        cmin[x]=INT_MAX;
        uz[x]=0;
    }
    cmin[start]=0;
    for(j=1;j<=n;j++)
    {
        minim=INT_MAX;
        for(x=1;x<=n;x++)
            if(!uz[x] && cmin[x]<minim)
            {
                minim=cmin[x];
                vfmin=x;
            }
        uz[vfmin]=1;
        cost_apm+=minim;

        for(i=0;i<G[vfmin].size();i++)
        {
            if(!uz[G[vfmin][i].vf] &&
               cmin[G[vfmin][i].vf]>G[vfmin][i].c)
            {
                cmin[G[vfmin][i].vf]=G[vfmin][i].c;
                prec[G[vfmin][i].vf]=vfmin;
            }
        }
    }
}
void afisare()
{
    int x;
    fout << cost_apm << '\n';
    fout << n-1 << '\n';

    for(x=1;x<=n;x++)
        if(prec[x])
            fout << x << ' ' << prec[x] << '\n';
}
int main()
{
    citire();
    prim(1);
    afisare();
    return 0;
}