#include <iostream>
#include <vector>
#include <set>
#include <queue>
#include <stack>
#include <math.h>
#include <cassert>
#include <bitset>
#include <map>
#include <algorithm>
#include <iterator>
#include <string>
#include <utility>
#include <numeric>
#include <regex>
#include <complex>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
using ll=long long;
using ull=unsigned long long;
using P=pair<ll,ll>;
template<typename T>using minque=priority_queue<T,vector<T>,greater<T>>;
template<typename T>bool chmax(T &a,const T &b){return (a<b?(a=b,true):false);}
template<typename T>bool chmin(T &a,const T &b){return (a>b?(a=b,true):false);}
template<typename T1,typename T2>
ostream &operator<<(ostream &os,const pair<T1,T2>&p){
  os<<p.first<<" "<<p.second;
  return os;
}
template<typename T1,typename T2>
istream &operator>>(istream &is,pair<T1,T2>&p){
  is>>p.first>>p.second;
  return is;
}
template<typename T>
istream &operator>>(istream &is,vector<T> &a){
  for(auto &i:a)is>>i;
  return is;
}
#define reps(i,a,n) for(int i=(a);i<(n);i++)
#define rep(i,n) reps(i,0,n)
#define all(x) x.begin(),x.end()
ll myceil(ll a,ll b){return (a+b-1)/b;}
int n;
vector<vector<int>>to;
vector<bool>dp,ans;
void dfs(int x,int p){
  dp[x]=true;
  for(auto i:to[x]){
    if(i==p)continue;
    dfs(i,x);
    if(dp[i])dp[x]=false;
  }
}
void dfs2(int x,int p){
  ans[x]=true;
  for(auto i:to[x])if(dp[i])ans[x]=false;
  int s=to[x].size();
  vector<bool>lft(s),rht(s);
  rep(i,s)lft[i]=rht[i]=dp[to[x][i]];
  reps(i,1,s)lft[i]=lft[i]||lft[i-1];
  for(int i=s-2;i>=0;i--)rht[i]=rht[i]||rht[i+1];
  rep(i,s){
    if(to[x][i]==p)continue;
    dp[x]=true;
    if(0<i&&lft[i-1])dp[x]=false;
    if(i<s-1&&rht[i+1])dp[x]=false;
    dfs2(to[x][i],x);
  }
}
int main(){
  cin>>n;
  to.resize(n);
  rep(i,n-1){
    int a,b;
    cin>>a>>b;
    a--,b--;
    to[a].push_back(b);
    to[b].push_back(a);
  }
  dp.resize(n),ans.resize(n);
  dfs(0,-1);
  dfs2(0,-1);
  vector<int>id;
  rep(i,n)if(ans[i])id.push_back(i+1);
  cout<<id.size()<<'\n';
  for(auto i:id)cout<<i<<'\n';
}