#include<fstream>
#include<algorithm>
using namespace std;
struct muchie
{
    int x,y,c;
};
muchie v[400000];
int cost,t[400000],sol[400000],n,nr,m,sum;
ifstream f("kruskal.in");
ofstream g("kruskal.out");
int test (muchie a,muchie d)
{
    return a.c<d.c;
}
int getroot(int x) {
  if(t[x] != x) {
    t[x] = getroot(t[x]);
  }
  return t[x];
}

void reunion(int x, int y) {
  t[getroot(x)] = getroot(y);
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=m;++i)
        f>>v[i].x>>v[i].y>>v[i].c;
    sort(v+1,v+m+1,test);
    for(int i=1;i<=n;++i)
        t[i]=i;
   nr=1;
   sol[1]=1;sum=v[1].c;
    t[v[1].y]=t[v[1].x];
    for(int i=2;i<=m and nr<n-1;++i)
    {
        if (getroot(v[i].x)!=getroot(v[i].y)) continue;
        nr++;
        sum+=v[i].c;
        sol[nr]=i;int z=t[v[i].y];
        //for(int j=1;j<=n;++j)
          //  if(t[j]==z) t[j]=t[v[i].x];
          reunion(v[i].x,v[i].y);
    }
        g<<sum<<endl<<n-1<<endl;
        for(int i=1;i<=nr;++i)
            g<<v[sol[i]].x<<" "<<v[sol[i]].y<<endl;
g.close();
return 0;
}