#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int n,m,fa[200],b[200];
struct node {
	int x,y;
} a[5010];
inline bool cmp(node x,node y) {
	if(x.x==y.x) {
		return x.y<y.y;
	} else {
		return x.x<y.x;
	}
}
inline int findd(int x) {
	if(fa[x]==x) {
		return x;
	} else {
		return fa[x]=findd(fa[x]);
	}
}
inline void finding(int x,int y) {
	int xx=findd(x),yy=findd(y);
	fa[yy]=fa[xx];
}
int main() {
	ios::sync_with_stdio(0);
	cin>>n>>m;

	for(int i=1; i<=m; i++) {
		cin>>a[i].x>>a[i].y;
		if(a[i].y<a[i].y){
			swap(a[i].x,a[i].y);
		}
	}
	sort(a+1,a+m+1,cmp);
	for(int i=1;i<=m ;i++){
		int f=0;
		for(int j=1;j<=n;j++){
			fa[j]=j;
		}
		for(int j=1;j<=m;j++){
			if(j!=i){
				finding(a[j].x,a[j].y);
			}
		}
		for(int j=2;j<=n;j++){
			if(fa[findd(j)]!=fa[findd(j-1)]){
				cout<<a[i].x<<" "<<a[i].y<<endl;
				break;
			}
		}
	}
	return 0;
}