#include <bits/stdc++.h>

using namespace std;

int N;
vector< int > g[100000];

bool dfs(int idx, int par) {
  for(auto &to : g[idx]) {
    if(to == par) continue;
    if(!dfs(to, idx)) return true;
  }
  return false;
}

int main() {
  cin >> N;
  for(int i = 1; i < N; i++) {
    int x, y;
    cin >> x >> y;
    --x, --y;
    g[x].push_back(y);
    g[y].push_back(x);
  }
  vector< int > ans;
  for(int i = 0; i < N; i++) {
    if(!dfs(i, -1)) ans.push_back(i);
  }
  cout << ans.size() << endl;
  for(auto &p : ans) cout << p + 1 << endl;
}