#include <bits/stdc++.h>
using namespace std;
vector<int> v[200009];
vector<int> rev[200009];
int rededge = 0, ar[200009], br[200009], vis[200009];
void dfs(int n, int e, int r) {
  vis[n] = 1;
  ar[n] = e;
  br[n] = r;
  int i;
  for (i = 0; i < v[n].size(); i++) {
    int uu = v[n][i];
    if (vis[uu] == 0) {
      dfs(uu, e + 1, r);
    }
  }
  for (i = 0; i < rev[n].size(); i++) {
    int uu = rev[n][i];
    if (vis[uu] == 0) {
      rededge++;
      dfs(uu, e, r + 1);
    }
  }
}
int main() {
  memset(vis, 0, sizeof(vis));
  int n;
  cin >> n;
  for (int i = 0; i < n - 1; i++) {
    int x, y;
    scanf("%d %d", &x, &y);
    v[x].push_back(y);
    rev[y].push_back(x);
  }
  ar[1] = 0;
  br[1] = 0;
  dfs(1, 0, 0);
  int mx = INT_MAX;
  queue<int> q;
  for (int i = 1; i <= n; i++) {
    int x = rededge - br[i] + ar[i];
    if (mx > x) {
      while (!q.empty()) {
        q.pop();
      }
      q.push(i);
      mx = x;
    } else if (mx == x) {
      q.push(i);
    }
  }
  cout << mx << endl;
  while (!q.empty()) {
    cout << q.front() << " ";
    q.pop();
  }
  cout << endl;
}
