#include <bits/stdc++.h>
using namespace std;
const int maxn = 2 * 1000 * 100 + 3;
int dp[maxn], ans[maxn], tey[maxn][2];
vector<pair<int, bool> > e[maxn];
void dfs(int source, int par, int dw, int up) {
  for (int i = 0; i < e[source].size(); i++)
    if (e[source][i].first != par)
      dfs(e[source][i].first, source, dw + e[source][i].second,
          up + !e[source][i].second),
          dp[source] += dp[e[source][i].first] + !e[source][i].second;
  tey[source][0] = dw;
  tey[source][1] = up;
}
int main() {
  int n, fi, se;
  cin >> n;
  for (int i = 0; i < n - 1; i++)
    cin >> fi >> se, e[fi].push_back(make_pair(se, 1)),
        e[se].push_back(make_pair(fi, 0));
  dfs(1, 0, 0, 0);
  ans[1] = dp[1];
  int mini = ans[1];
  for (int i = 2; i <= n; i++)
    ans[i] = ans[1] - tey[i][1] + tey[i][0], mini = min(ans[i], mini);
  vector<int> q(0);
  for (int i = 1; i <= n; i++)
    if (ans[i] == mini) q.push_back(i);
  cout << mini << endl;
  for (int i = 0; i < q.size(); i++) cout << q[i] << " ";
  cout << endl;
  return 0;
}
