#include <bits/stdc++.h>
using namespace std;
vector<int> gr[200005];
map<pair<int, int>, int> inv;
int ans[200005];
int dfs(int src, int par) {
  int res = inv[{par, src}];
  for (auto nbr : gr[src]) {
    if (nbr != par) {
      res += dfs(nbr, src);
    }
  }
  return res;
}
void dfs2(int src, int par) {
  for (auto nbr : gr[src]) {
    if (nbr != par) {
      if (inv[{src, nbr}])
        ans[nbr] = ans[src] - 1;
      else
        ans[nbr] = ans[src] + 1;
      dfs2(nbr, src);
    }
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  for (int i = 0; i < n - 1; i++) {
    int u, v;
    cin >> u >> v;
    gr[u].push_back(v);
    gr[v].push_back(u);
    inv[{u, v}] = 0;
    inv[{v, u}] = 1;
  }
  ans[1] = dfs(1, -1);
  dfs2(1, -1);
  int mn = INT_MAX;
  for (int i = 1; i <= n; i++) {
    mn = min(mn, ans[i]);
  }
  vector<int> res;
  for (int i = 1; i <= n; i++) {
    if (ans[i] == mn) res.push_back(i);
  }
  cout << mn << "\n";
  for (auto x : res) cout << x << " ";
  return 0;
}
