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

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

struct muchie{int x,y,c;};
int m,n,L[1000];
muchie v[1000],h[1000];
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;
	}