#include <bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:1024000000,1024000000")
vector<int> m[200010];
vector<int> in[200010];
int ans[200010];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  srand(__rdtsc());
  int n;
  cin >> n;
  int u, v;
  for (int i = 1; i < n; i++) {
    cin >> u >> v;
    m[u].push_back(v);
    in[v].push_back(u);
  }
  queue<int> q;
  q.push(1);
  int t = 0;
  memset(ans, 0, sizeof(ans));
  ans[1] = -1;
  while (!q.empty()) {
    u = q.front();
    q.pop();
    for (int i = 0; i < m[u].size(); i++)
      if (ans[m[u][i]] == 0) {
        q.push(m[u][i]);
        ans[m[u][i]] = -1;
      }
    for (int i = 0; i < in[u].size(); i++)
      if (ans[in[u][i]] == 0) {
        ans[in[u][i]] = -1;
        q.push(in[u][i]);
        t++;
      }
  }
  memset(ans, -1, sizeof(ans));
  ans[1] = t;
  q.push(1);
  while (!q.empty()) {
    u = q.front();
    q.pop();
    for (int i = 0; i < m[u].size(); i++)
      if (ans[m[u][i]] == -1) {
        q.push(m[u][i]);
        ans[m[u][i]] = ans[u] + 1;
      }
    for (int i = 0; i < in[u].size(); i++)
      if (ans[in[u][i]] == -1) {
        q.push(in[u][i]);
        ans[in[u][i]] = ans[u] - 1;
      }
  }
  int answer = ans[1];
  for (int i = 2; i <= n; i++)
    if (ans[i] < answer) answer = ans[i];
  cout << answer << endl;
  for (int i = 1; i <= n; i++)
    if (ans[i] == answer) cout << i << " ";
  cout << endl;
  return 0;
}
