#include <bits/stdc++.h>
using namespace std;
int n;
vector<pair<int, int> > g[200001];
int visited[200001];
int f2[200001];
int f1[200001];
int total;
void fuck1(int u, int c) {
  visited[u] = 1;
  f1[u] = c;
  for (int i = 0; i < g[u].size(); ++i) {
    int v = g[u][i].first;
    if (!visited[v]) {
      fuck1(v, c + 1);
    }
  }
}
void fuck2(int u, int c) {
  visited[u] = 1;
  f2[u] = c;
  for (int i = 0; i < g[u].size(); ++i) {
    int v = g[u][i].first;
    if (!visited[v]) {
      total += g[u][i].second;
      fuck2(v, c + g[u][i].second);
    }
  }
}
int main() {
  int u, v;
  scanf("%d", &n);
  for (int i = 0; i < n - 1; ++i) {
    scanf("%d", &u);
    scanf("%d", &v);
    g[u].push_back((pair<int, int>)make_pair(v, 0));
    g[v].push_back((pair<int, int>)make_pair(u, 1));
  }
  fuck1(1, 0);
  memset(visited, 0, sizeof(visited));
  fuck2(1, 0);
  int ans = 1000000007;
  for (int i = 1; i <= n; ++i) {
    ans = min(ans, total - f2[i] + f1[i] - f2[i]);
  }
  vector<int> yahan;
  yahan.clear();
  for (int i = 1; i <= n; ++i) {
    if (total - f2[i] + f1[i] - f2[i] == ans) {
      yahan.push_back(i);
    }
  }
  cout << ans << endl;
  for (int i = 0; i < yahan.size(); ++i) {
    cout << yahan[i] << " ";
  }
  printf("\n");
  return 0;
}
