// includes
#include <cstdio>
#include <cstdint>
#include <iostream>
#include <iomanip>
#include <string>
#include <queue>
#include <stack>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <utility>
#include <functional>
#include <cmath>
#include <climits>
#include <bitset>
#include <list>
#include <random>

// macros
#define ll long long int
#define pb emplace_back
#define mk make_pair
#define pq priority_queue
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())

using namespace std;

//  types
typedef pair<int, int> P;
typedef pair<ll, int> Pl;
typedef pair<ll, ll> Pll;
typedef pair<double, double> Pd;
 
// constants
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1e9 + 7;

// solve
template <class T>bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;}
template <class T>bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;}

vector<int> edge[100001];
map<int, int> mp[100001];

int dfs(int i, int j){
  if(sz(edge[i]) == 0 && j != -1)return 0;
  if(mp[i].find(j) != mp[i].end())return mp[i][j];
  int res = 0;
  if(mp[i].size()){
    auto p = *mp[i].begin();
    int c = p.first;
    res = p.second;
    if(c >= 0)res += (dfs(c, i) == 0 ? 1 : 0);
    if(j >= 0)res -= (dfs(j, i) == 0 ? 1 : 0);
  }else{
    for(auto c: edge[i]){
      if(c == j)continue;
      res += (dfs(c, i) == 0 ? 1 : 0);
    }
  }
  return mp[i][j] = res;
}

int main(int argc, char const* argv[])
{
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  rep(i, n - 1){
    int a, b;
    cin >> a >> b, a--, b--;
    edge[a].pb(b);
    edge[b].pb(a);
  }
  vector<int> ans;
  for(int i = 0; i < n; i++){
    if(dfs(i, -1) == 0)ans.pb(i+1);
  }
  cout << sz(ans) << endl;
  for(int i = 0; i < sz(ans); i++)cout << ans[i] << endl;
	return 0;
}