#include<fstream>
#include<stdlib>
#define endl "\n"

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 find(int x){
if(x==L[x]) return x;
return find(L[x]);
}

void Union(int x,int y){
int px=find(x);
int py=find(y);
L[py]=px;
}

int max(int x,int y){
if(x>y) return x;
return y;
}

int min(int x,int y){
if(x<y) return x;
return y;
}

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

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