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

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

struct muchie{ int x,y,c;};
int n,m,L[100];
muchie v[100],h[100];

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;
}

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]; }
	out<<ct<<endl;
for(i=0;i<n-1;i++)
	out<<h[i].x<<" "<<h[i].y<<" "<<h[i].c<<endl;
	}