#include <fstream>
#include <algorithm>
#define NMAX 200002
#define MMAX 400002
using namespace std;
ifstream  fin("apm.in");
ofstream fout("apm.out");
int N,M,ans,cnt,rad[NMAX],nr[NMAX];

struct muchie
{
    int x,y,c;
}v[MMAX];

struct solutie
{
    int x,y;
}sol[MMAX];

void citire()
{
    fin>>N>>M;

    for(int i=1; i<=M; i++)
    {
        fin>>v[i].x>>v[i].y>>v[i].c;
    }
}

bool cmp(muchie a, muchie b)
{
    return a.c<b.c;
}

int Find(int x)
{
    if(x==rad[x])
    {
        return x;
    }
    else
    {
        rad[x]=Find(rad[x]);
        return rad[x];
    }
}

void Union(int a, int b)
{
    if(nr[a]>=nr[b])
    {
        rad[b]=a;
        nr[a]+=nr[b];
    }
    else
    {
        rad[a]=b;
        nr[b]+=nr[a];
    }
}

int main()
{
    citire();

    for(int i=1; i<=N; i++)
    {
        rad[i]=i;
        nr[i]=1;
    }

    sort(v+1,v+1+M,cmp);
    ans=cnt=0;

    for(int i=1; i<=M; i++)
    {
        int x,y;
        x=Find(v[i].x);
        y=Find(v[i].y);

        if(x!=y)
        {
            Union(x,y);
            ans+=v[i].c;
            cnt++;
            sol[cnt].x=v[i].x;
            sol[cnt].y=v[i].y;
        }
    }

    fout<< ans << "\n";

    fout<< cnt << "\n";

    for(int i=1; i<=cnt; i++)
    {
        fout<< sol[i].x << " " << sol[i].y << "\n";
    }

    return 0;
}