#include <bits/stdc++.h>

using namespace std;

ifstream f ("apm.in");
ofstream g ("apm.out");

int n,m;
int cost;
int par[500005];

struct el
{
    int x;
    int y;
    int cost;

};
el a[500005];
el afis[500005];
int cmp (el A, el B)
{
    if(A.cost<B.cost)
        return 1;
    return 0;

}

int Find(int x)
{
    int rad=x;
    while(par[rad]!=0)
    {
        rad=par[rad];
    }
    while(par[x]!=0)
    {
        int aux=par[x];
        par[x]=rad;
        x=aux;
    }
    return rad;

}

int main()
{
    f>>n>>m;
    for(int i=1; i<=m; ++i)
    {

        f>>a[i].x>>a[i].y>>a[i].cost;

    }
    sort(a+1, a+m+1, cmp);
    int puse=0;
    int i=1;
    while(puse<n)
    {

        int par1=Find(a[i].x);
        int par2=Find(a[i].y);

        if(par1!=par2 || par1==0 || par2==0)
        {
            par[par2]=par1;
            cost+=a[i].cost;
            afis[puse].x=a[i].x;
            afis[puse].y=a[i].y;
            ++puse;

        }
        ++i;
    }
    g<<cost<<"\n";
    g<<n-1<<"\n";
    for(int i=0; i<n-1; ++i)
        g<<afis[i].x<<" "<<afis[i].y<<"\n";
    return 0;
}