#include<bits/stdc++.h>
using namespace std;
#define int long long
#define inf 5e18
#define nl '\n'
const int N = 2e5+1;
vector<int> g[N];
vector<int> ans;
int n, m;
void dfs(int v, int p){
for(int i=2; i <= g[v].size()-1; i++){
ans.push_back(i);
}
for(int ch : g[v]){
if(ch != p) dfs(ch, v);
}
}
inline void solve(){
cin>>n>>m;
for(int i=1; i<n+m; i++){
int a, b;
cin>>a>>b;
g[a].push_back(b);
g[b].push_back(a);
}
dfs(n+m, 0);
for(int x : ans) cout<<x<<" 1"<<nl;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);cout.tie(NULL);
int t = 1;
//cin>>t;
while(t--) solve();
return 0;
}
