#include <bits/stdc++.h>
using i64 = long long;
using std::cout;
using std::endl;
using std::cin;

int n;
std::vector<std::vector<int>> g;
std::vector<std::map<int, int>> dp;
void dfs(int v, int par = -1) {
	if(dp[v].count(par)) return;
	
	std::set<int> st;
	for(auto e : g[v]) {
		if(e == par) continue;
		dfs(e, v);
		st.insert(dp[e][v]);
	}
	
	int tmp = 0;
	while(st.count(tmp)) tmp++;
	dp[v][par] = tmp;
	return;
}

int main() {
	scanf("%d", &n); g.resize(n); dp.resize(n);
	for(int i = 0; i < n - 1; i++) {
		int a, b; scanf("%d%d", &a, &b);
		
		g[a - 1].push_back(b - 1);
		g[b - 1].push_back(a - 1);
	}
	
	std::vector<int> ans;
	for(int i = 0; i < n; i++) {
		dfs(i);
		if(!dp[i][-1]) ans.push_back(i + 1);
	}
	printf("%d\n", ans.size());
	for(auto v : ans) printf("%d\n", v);
	return 0;
}