#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;


ifstream fin("apm.in");
ofstream fout("apm.out");


const int nmax=200005;
int cnt,sum;
int v[nmax][2];
int n,m;
int x,y,c;
int t[nmax];


struct Edge
{
    int x,y,c;
    bool operator < (const Edge &A) const
    {
        return c < A.c;
    }
};
Edge E[2*nmax];


void read()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>E[i].x>>E[i].y>>E[i].c;
    }
    sort(E+1,E+m+1);
}


void Union(int x,int y)
{
    t[x]=y;
}


int Find(int x)
{
    int rad=x;
    while(t[rad]!=(-1))
    {
        rad=t[rad];
    }
    int aux;
    while(x!=rad)
    {
        aux=t[x];
        t[x]=rad;
        x=aux;
    }
    return rad;
}


void solve()
{
    for(int i=1;i<=n;i++) t[i]=-1;
    for(int i=1;i<=m;i++)
    {
        int r1=Find(E[i].x);
        int r2=Find(E[i].y);
        if(r1!=r2)
        {
            Union(r1,r2);
            sum+=E[i].c;
            v[++cnt][0]=E[i].x;
            v[cnt][1]=E[i].y;
        }
    }
    fout<<sum<<"\n";
    fout<<cnt<<"\n";
    for(int i=1;i<=cnt;i++)
    {
        fout<<v[i][0]<<" "<<v[i][1]<<"\n";
    }
}


int main()
{
    read();
    solve();
    return 0;
}