Untitled

#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("ssse3,sse4,popcnt,lzcnt,abm,bmi,bmi2,mmx,avx2,fma")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
ll MOD = 998244353;
ll mod = 1e9+7;
double eps = 1e-3;
double ep = 1e-8;
#define rep(i, n) for(ll i = 0, _n = (ll)(n); i < _n; i++)
#define endl '\n' //comment out for interactive problems

vector<pair<ll,ll>> adj[200005];
vector<ll> cnt(200005,0);
ll maxc = 0, c = 0;

void dfs(ll u, ll p, ll d){
    cnt[u] = d;
    maxc = max(maxc,d);
    for(auto v: adj[u]){
        if(v.first!=p){
            dfs(v.first,u,d+v.second);
            if (v.second == 1) c++;
        }
    }
}



void solve(){ 
    ll n;
    cin>>n;
    rep(i,n-1){
        ll u,v;
        cin>>u>>v;
        adj[u].push_back({v,-1});
        adj[v].push_back({u,1});
    }
    dfs(1,0,0);
    vector<ll> ans;
    rep(i,n){
        if(cnt[i+1]==maxc){
            ans.push_back(i+1);
        }
    }
    cout<<c - maxc<<endl;
    rep(i,ans.size()){
        cout<<ans[i]<<" ";
    }
}
    
    

int main(){
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    ios_base::sync_with_stdio(false); cin.tie(0); 
    ll t=1;
    //cin>>t;
    for (ll i=1; i<=t; i++){
        //cout<<"Case #"<<i<<": ";
		solve();
    }
    return 0;
}