1. A. Did We Get Everything Covered?(构造、思维)

#include <bits/stdc++.h>
#define int long long
#define rep(i,a,b) for(int i = (a); i <= (b); ++i)
#define fep(i,a,b) for(int i = (a); i >= (b); --i)
#define pii pair<int, int>
#define ll long long
#define db double
#define endl '\n'
#define x first
#define y second
#define pb push_back
#define vi vector<int>

using namespace std;

void solve() {
   
	int n;
	cin>>n;
	vector<vi>g(n+1);
	vi d(n+1);
	rep(i,1,n){
   
		int u,v;
		cin>>u>>v;
		g[u].pb(v);
		g[v].pb(u);
		d[u]++;
		d[v]++;
	}
	queue<int>q;
	rep(i,1,n){
   
		if(d[i]==1){
   
			q.push(i);
		}
	}
	while(q.size()){
   
		auto u=q.front();
		q.pop();
		for(auto v:g[u]){
   
			if(--d[v]==1){
   
				q.push(v);
			}	
		}
	}
	rep(i,1,n){
   
		if(d[i]>=2){
   
			cout<<i<<endl;
		}
	}
}

signed main() {
   
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
//	freopen("1.in", "r", stdin);
	int _;
//	cin>>_;
//	while(_--)
	solve();
	return 0;
}