#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;
vector<int> g[100000];
bool w[100000];
int wct[100000];
bool wp[100000];
bool used[100000];
void dfs(int x){
	used[x]=1;
	w[x]=1;
	for(auto y:g[x]){
		if(used[y]) continue;
		dfs(y);
		if(w[y]){
			w[x]=0;
			wct[x]++;
		}
	}
}
vector<int> ans;
void dfs2(int x){
	used[x]=1;
	int ct0=wct[x];
	if(wp[x]) ct0++;
	if(ct0==0) ans.push_back(x);
	for(auto y:g[x]){
		if(used[y]) continue;
		int ct=wct[x];
		if(w[y]) ct--;
		if(wp[x]) ct++;
		if(ct==0) wp[y]=1;
		dfs2(y);
	}
}
int main()
{
	int n; cin>>n;
	for(int i=0; i<n-1; i++){
		int a, b;
		cin>>a>>b;
		a--; b--;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	dfs(0);
	fill(used, used+n, 0);
	dfs2(0);
	sort(ans.begin(), ans.end());
	cout<<ans.size()<<endl;
	for(auto x:ans) cout<<x+1<<endl;
	return 0;
}