#include<fstream>
#include<vector>
#include<queue>
#define NM 200001
#define INF 2000000001
#include<stdio.h>

using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
int n, m, d[NM],t[NM],viz[NM],w;
long long ct;
struct  pereche
{
    int y,c;
};

struct compar
{
    bool operator()(int x,int y)
    {
        return d[x]>d[y];
    }
};

vector<pereche> G[NM];

priority_queue <int, vector<int>, compar> q;

void Citeste()
{
    int i, x,y;
    pereche u;
    f>>n>>m;
    for (i=1; i<=m; i++)
    {
        f>>x>>y>>u.c;

        u.y=y;
        G[x].push_back(u);

        u.y=x;
        G[y].push_back(u);

    }

}
void Prim()
{
    int z,lg,i,nr;

    for (i=2; i<=n; i++) d[i]=INF;
    d[1]=0;

    q.push(1);
    nr=0;

    while (nr<n)
    {

        int j,im,y,c;
        pereche p;

        im=q.top();
        q.pop();

        if(viz[im]==1)
            continue;

        viz[im]=1;
        nr++;
        ct=ct+d[im];

        for(j=0; j<G[im].size(); j++)
        {
            y=G[im][j].y;
            c=G[im][j].c;

            if(viz[y]==0 && c<d[y])
            {
                t[y]=im;
                d[y]=c;
                q.push(y);
            }
        }

    }
}


void Scrie()
{
    int i;
    g<<ct<<'\n';
     g<<n-1<<'\n';
    for (i=2; i<=n; i++)
        g<<i<<' '<<t[i]<<'\n';
}
int main()
{
    Citeste();
    Prim();
    Scrie();
    return 0;
}