#include<bits/stdc++.h>
using namespace std;

vector<int> g[100000];
int N; 
// 想定MLE ?
auto dp = vector< vector<char> >(100000, vector<char>(100000, -1));

bool dfs(int v, int p) {
  if(~((int)dp[v][p])) return (int) dp[v][p];
  bool flag = 0;
  for(int u : g[v]) if(u != p) flag |= dfs(u, v);
  return dp[v][p] = !flag;
}

bool isTree() {
  bool flag[N] = {};
  function<void(int, int)> check = [&](int v, int p) {
    flag[v] = 1;
    for(int u : g[v]) if(u != p) check(u, v);
  };
  check(0, -1);
  bool all = 1;
  for(int i = 0; i < N; i++) all &= flag[i];
  return all;
}

int main() {
  cin >> N;
  for(int i = 0; i < N - 1; i++) {
    int a, b; cin >> a >> b; a--; b--;
    assert(0 <= a && a < N && 0 <= b && b < N);
    g[a].emplace_back(b);
    g[b].emplace_back(a);
  }

  assert(isTree());
  
  vector<int> ans; ans.reserve(N);
  for(int i = 0; i < N; i++)
    if(dfs(i, -1)) ans.emplace_back(i);

  cout << ans.size() << endl;
  for(int el : ans) cout << el + 1 << endl;
}