#include<cstdio>
#include<set>
#include<vector>
#define dmax 2000000000
using namespace std;
vector< pair<int,int> >L[200100];
vector< pair<int,int> >::iterator it;
int n,m,i,j,d[200100],v[200100],l[400100],C[400100],t[400100],sum,nr,a,b,c,ok,vmin,poz,h[400100],dh,x[400100],ih;
FILE *f,*g;
void chg(int &x,int &y){
    int aux=x;
    x=y;
    y=aux;
}
void del(){
    h[1]=h[dh--];
    int p=1;
    int c=2;
    x[h[1]]=1;
    while(c<=dh){
        if(d[h[c]]>d[h[c+1]]&&c<dh)
            c++;
        if(d[h[c]]<d[h[p]]){
            chg(h[c],h[p]);
            x[h[c]]=c;
            x[h[p]]=p;
            p=c;
            c*=2;
        }
        else
            break;
    }
}
void upd(int poz){
    int c=poz;
    int p=poz/2;
    while(p>0){
        if(d[h[c]]<d[h[p]]){
            chg(h[c],h[p]);
            x[h[c]]=c;
            x[h[p]]=p;
            c=p;
            p/=2;
        }
        else
            break;
    }
}
int main(){
    f=fopen("apm.in","r");
    g=fopen("apm.out","w");
    fscanf(f,"%d%d",&n,&m);
    for(i=1;i<=m;i++){
        fscanf(f,"%d%d%d",&a,&b,&c);
        L[a].push_back(make_pair(b,c));
        L[b].push_back(make_pair(a,c));
    }
    for(i=2;i<=n;i++){
        d[i]=dmax;
    }
    dh=1;
    h[1]=x[1]=1;
    while(dh){
        poz=h[1];
        del();
        sum+=d[poz];
        l[++nr]=t[poz];
        C[nr]=poz;
        v[poz]=1;
        for(i=0;i<L[poz].size();i++){
            a=L[poz][i].first;
            if(d[a]>L[poz][i].second){
                ih=(d[a]!=dmax);
                d[a]=L[poz][i].second;
                t[a]=poz;
                if(ih==0){
                    dh++;
                    h[dh]=a;
                    x[a]=dh;
                    upd(dh);
                }
                else
                    upd(x[a]);
            }
        }
    }
    fprintf(g,"%d\n%d\n",sum,nr-1);
    for(i=2;i<=nr;i++){
        fprintf(g,"%d %d\n",l[i],C[i]);
    }


    fclose(f);
    fclose(g);
    return 0;
}