#include<fstream>
#include<vector>
#include<cstring>
#include<bitset>
using namespace std;
#define NMAX 200005
#define mp make_pair
ifstream fin("apm.in");
ofstream fout("apm.out");
vector < pair <int,int> > v[NMAX],V;
bitset <NMAX> viz;
int n,m,x,y,c,dh,cost,D[NMAX],H[NMAX],P[NMAX],T[NMAX];
int extrage_min()
{
    int p=H[1];
    P[H[dh]]=0, H[1]=H[dh--], P[H[1]]=1;
    int t=1,f=2,aux;
    while (f<=dh)
    {
        if (f<dh && D[H[f+1]]<D[H[f]]) ++f;
        if (D[H[t]]<=D[H[f]]) break;
        aux=H[t], H[t]=H[f], H[f]=aux;
        P[H[t]]=t, P[H[f]]=f;
        t=f, f=t<<1;
    }
    return p;
}
void actualizare(int nr, int poz)
{
    if (poz>dh || poz<1)
        poz=dh+1, H[++dh]=nr, P[H[dh]]=dh;
    int f=poz,t=f>>1,aux;
    while (t)
    {
        if (D[H[t]]<=D[H[f]]) break;
        aux=H[t], H[t]=H[f], H[f]=aux;
        P[H[t]]=t, P[H[f]]=f;
        f=t, t=f>>1;
    }
}
int main()
{
    int i;
    fin>>n>>m;
    memset(D,0x3f,sizeof(D));
    for (i=0;i<m;++i)
    {
        fin>>x>>y>>c;
        v[x].push_back(mp(y,c));
        v[y].push_back(mp(x,c));
    }
    D[1]=0, viz[1]=1;
    for (auto fiu: v[1])
    {
        D[fiu.first]=fiu.second;
        T[fiu.first]=1;
        actualizare(fiu.first,0);
    }
    while (dh>0)
    {
        x=extrage_min();
        cost+=D[x], viz[x]=1, V.push_back(mp(x,T[x]));
        for (auto fiu: v[x])
            if (!viz[fiu.first] && D[fiu.first]>fiu.second)
            {
                D[fiu.first]=fiu.second;
                T[fiu.first]=x;
                actualizare(fiu.first,P[fiu.first]);
            }
    }
    fout<<cost<<"\n"<<n-1<<"\n";
    for (auto muchie: V)
        fout<<muchie.first<<" "<<muchie.second<<"\n";
    return 0;
}