#include<fstream.h>
#include<stdlib.h>
#define NM 200001
#define MM 400001
#define endl "\n"

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

struct muchie{int x,y,c;};

int n,m,L[NM];

muchie v[MM],h[NM];

void citire(){
int i;
in>>n>>m;
for(i=0;i<m;i++)
	  in>>v[i].x>>v[i].y>>v[i].c;
}

int fcmp(void const*a,void const*b){
return ((muchie*)a)->c-((muchie*)b)->c;
}


int main(){
int i,ms=0,j,ct=0;
citire();
qsort(v,m,sizeof(v[0]),fcmp);
for(i=1;i<=n;i++) L[i]=i;
i=0;
while(ms<n-1){
	while(L[v[i].x]==L[v[i].y]) i++;
	h[ms]=v[i];
	ms++;
	ct+=v[i].c;
 for(j=1;j<=n;j++)
	  if(L[j]==L[v[i].y])
		  L[j]=L[v[i].x];
		  }
 out<<ct<<n-1<<endl;
for(i=0;i<n-1;i++)
	 out<<h[i].x<<" "<<h[i].y<<" "<<endl;
	 return 0;
	 }