#include <iostream>
#include <algorithm>
#include <cstdio>
#include <queue>
#include <vector>
#define nmax 200001
#define inf 1<<30
using namespace std;
FILE *f=fopen("apm.in","r"),*g=fopen("apm.out","w");
struct muc{
    int c,d;
};
int d[nmax],viz[nmax],p[nmax];
struct cmp{
    int operator()(int x, int y)
    {
        return d[x]>d[y];
    }
};
priority_queue <int, vector <int>, cmp> q;
vector <muc> l[nmax];
int main()
{
    int i,j,n,m,x,y,s=0; muc aux;
    fscanf(f,"%d %d",&n,&m);
    for(i=1;i<=m;i++)
    {
        fscanf(f,"%d %d %d",&x,&y,&aux.c);
        aux.d=y;
        l[x].push_back(aux);
        aux.d=x;
        l[y].push_back(aux);
    }
    for(i=2;i<=n;i++)
        d[i]=inf;
    q.push(1);
    while(!q.empty())
    {
        x=q.top();
        q.pop();
        viz[x]=1;
        for(i=0;i<l[x].size();i++)
        {
            y=l[x][i].d;
            if(d[y]>l[x][i].c&&!viz[y])
            {
                d[y]=l[x][i].c;
                p[y]=x;
                q.push(y);
            }
        }
    }
    for(i=1;i<=n;i++)
        s+=d[i];
    fprintf(g,"%d\n%d\n",s,n-1);
    for(i=2;i<=n;i++)
        fprintf(g,"%d %d\n",i,p[i]);
    fclose(f);
    fclose(g);
    return 0;
}