#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 = 0, int par = -1, bool f = true) {
	if(dp[v].count(par)) return;
	
	int ret = 0;
	if(f || par == -1) {
		for(auto e : g[v]) {
			if(e == par) continue;
			dfs(e, v, f);
			ret += !dp[e][v];
		}
	} else {
		dfs(v, -1, f);
		dfs(par, v, f);
		ret = dp[v][-1] - !dp[par][v];
	}
	
	dp[v][par] = ret;
	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);
	}
	
	dfs();
	std::vector<int> ans;
	for(int i = 0; i < n; i++) {
		dfs(i, -1, false);
		if(!dp[i][-1]) ans.push_back(i + 1);
	}
	printf("%d\n", ans.size());
	for(auto v : ans) printf("%d\n", v);
	return 0;
}