#include <bits/stdc++.h>

using namespace std;

int N;
vector<int> G[100010];
int dp[100010];
int dp2[100010];
bool ans[100010];

void dfs(int u, int p) {
  dp[u] = 1;
  for(int v : G[u]) {
    if(v == p) continue;
    dfs(v, u);
    dp[u] &= !dp[v];
  }
}

void dfs2(int u, int p, int carryin) {
  dp2[u] = 0;
  for(int v : G[u]) {
    if(v == p) dp2[u] += !carryin;
    else dp2[u] += !dp[v];
  }
  //cout<<u<<" "<<dp[u]<<" "<<G[u].size()<<endl;
  if(dp2[u] == G[u].size()) ans[u] = true;
  for(int v : G[u]) {
    if(v == p) continue;
    dfs2(v, u, dp2[u]-!dp[v]==G[u].size()-1);
  }
}


int main() {
  cin >> N;
  for(int i = 0; i < N-1; ++i) {
    int a, b;
    cin >> a >> b; --a, --b;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  dfs(0, -1);
  dfs2(0, -1, 0);
  cout << count(ans, ans+N, true) << endl;
  for(int i = 0; i < N; ++i) {
    if(ans[i]) cout << i+1 << endl;
  }

  return 0;
}