#include <iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<map>
#include<set>
#include<stack>
#include<queue>
#include<math.h>
using namespace std;
typedef long long ll;
#define int long long
typedef vector<int> VI;
typedef pair<int, int> pii;
typedef vector<pii> VP;
typedef vector<string> VS;
typedef priority_queue<int> PQ;
template<class T>bool chmax(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b < a) { a = b; return 1; } return 0; }
#define fore(i,a) for(auto &i:a)
#define REP(i,n) for(int i=0;i<n;i++)
#define eREP(i,n) for(int i=0;i<=n;i++)
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define eFOR(i,a,b) for(int i=(a);i<=(b);++i)
#define SORT(c) sort((c).begin(),(c).end())
#define rSORT(c) sort((c).rbegin(),(c).rend())
#define LB(x,a) lower_bound((x).begin(),(x).end(),(a))
#define UB(x,a) upper_bound((x).begin(),(x).end(),(a))
#define INF 1000000000
#define LLINF 9223372036854775807
#define mod 1000000007
//priority_queue<int,vector<int>, greater<int> > q2;

int N;
vector<VI>G;
bool dp[200010];
bool ans[200010];
int cnt[200010];

bool dfs(int now, int pa) {
	dp[now] = true;
	
	fore(to, G[now]) {
		if (to == pa)continue;
		if (dfs(to, now)) {
			dp[now] = false;
			cnt[now]++;
		}
	}
	return dp[now];
}

void dfs1(int now, int pa) {
	//cout << now << " " << pa << endl;
	ans[now] = 1;
	fore(to, G[now])if (dp[to])ans[now] = false;
	VI wins;
	fore(to, G[now])if (dp[to]) {
		//cout << now << " " << to << endl;
		wins.push_back(to);
	}

	if (wins.size() == 0) {
		dp[now] = 1;
		fore(to, G[now])if (to != pa)dfs1(to, now);
		return;
	}
	else if (1 < wins.size()) {
		dp[now] = 0;
		fore(to, G[now])if (to != pa)dfs1(to, now);
		return;
	}
	else {
		fore(to, G[now])if (to != pa) {
			if (wins[0] == to)dp[now] = 1;
			else dp[now] = 0;
			dfs1(to, now);
		}
		return;
	}
}

signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	cin >> N;
	G.resize(N);
	REP(i, N - 1) {
		int a, b; cin >> a >> b; a--; b--;
		G[a].push_back(b);
		G[b].push_back(a);
	}
	dfs(0,-1);
	dfs1(0, -1);
	VI a;
	REP(i, N) {
		if (ans[i])a.push_back(i + 1);
	}
	
	cout << a.size() << endl;
	REP(i, a.size())cout << a[i] << endl;

	return 0;
}