#include <bits/stdc++.h>
using namespace std;
int v[200005], RET = 0, r[200005];
vector<int> t[200005], t2[200005];
void vis(int n) {
  if (n == 1) v[n] = r[n] = 0;
  for (int i = 0; i < t[n].size(); i++) {
    if (v[t[n][i]] == -1) {
      v[t[n][i]] = v[n] + 1;
      r[t[n][i]] = r[n];
      vis(t[n][i]);
    }
  }
  for (int i = 0; i < t2[n].size(); i++) {
    if (v[t2[n][i]] == -1) {
      RET++;
      r[t2[n][i]] = r[n] + 1;
      v[t2[n][i]] = v[n] + 1;
      vis(t2[n][i]);
    }
  }
}
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n - 1; i++) {
    int u, v;
    cin >> u >> v;
    t[u].push_back(v);
    t2[v].push_back(u);
  }
  for (int i = 1; i <= n; i++) v[i] = -1;
  vis(1);
  int mn = 999999999;
  vector<int> lol;
  for (int i = 1; i <= n; i++) {
    int k = RET + v[i] - 2 * r[i];
    if (k < mn) {
      lol.clear();
      mn = k;
      lol.push_back(i);
    } else if (k == mn)
      lol.push_back(i);
  }
  cout << mn << endl;
  for (int i = 0; i < lol.size(); i++) {
    if (i) cout << " ";
    cout << lol[i];
  }
  cout << endl;
}
