#include<fstream.h>
#include<stdlib.h>

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

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

int n,m,L[1000];
muchie v[1000],h[1000];

void citire(){
     int i;
     fin>>n>>m;
     for(i=0;i<m;i++)
     fin>>v[i].x>>v[i].y>>v[i].c;
     }
int fcmp(void const*a,void const*b){
    return ((muchie*)a)->c-((muchie*)b)->c;
    }
void 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];
	   }
     fout<<ct<<endl;
     for(i=0;i<n-1;i++)
     fout<<h[i].x<<" "<<h[i].y<<" "<<h[i].c<<endl;
     }