#include<fstream>
#include<cstdlib>
using namespace std;
int md[200001],X[400001],Y[400001],C[400001],N,M,c,p[400001],l[200001],n=-1;
int mult(int x)
{
    if(md[x]==x)
        return x;
    md[x]=mult(md[x]);
    return md[x];
}
void reun(int x,int y)
{
    md[mult(x)]=mult(y);
}
int fs(const void *a, const void *b)
{
    return C[*(int *)a]-C[*(int *)b];
}
int main()
{
    ifstream f("apm.in");
    ofstream g("apm.out");
    f>>N>>M;
    int i;
    for(;i<M;++i)
    {
        f>>X[i]>>Y[i]>>C[i];
        md[i]=p[i]=i;
    }
    qsort((void *)p,M,sizeof(p[0]),fs);
    for(i=0;i<M;++i)
        if(mult(X[p[i]])!=mult(Y[p[i]]))
        {
            c+=C[p[i]];
            reun(X[p[i]],Y[p[i]]);
            l[++n]=p[i];
        }
    g<<c<<'\n'<<N-1<<'\n';
    for(i=0;i<N-1;++i)
        g<<X[l[i]]<<' '<<Y[l[i]]<<'\n';
}