//#include <tourist>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> p;
const int INF = 1e9;
const ll LINF = ll(1e18) + 1;
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)          \
    cout << #v << ":";    \
    for (auto x : v)      \
    {                     \
        cout << x << ' '; \
    }                     \
    cout << endl;
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 (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
//cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
int n;
vector<vector<int>> v;
vector<ll> dp;
vector<ll> dp1;
map<int,int> true_count;//prevを除くnozoku負け状態の数
bool dfs(int k,int prev){
    if(v[k].size()==1&&v[k][0]==prev){
        dp[k]=true;
        return true;
    }
    bool res=false;
    rep(i,v[k].size()){
        if(v[k][i]==prev)continue;
        bool temp=dfs(v[k][i],k);
        res|=temp;
    }
    if(res)
    dp[k]=false;
    else dp[k]=true;
    return dp[k];
}
void dfs1(int k,int prev){
    int sum=0;
    dp1[k]=true;
    rep(i,v[k].size()){
        if(dp[v[k][i]]){
            dp1[k]=false;
            sum++;
        }
    }
    if(sum==0){//全false
        //進められたらまけ
        dp[k]=true;
        rep(i,v[k].size()){
            if(v[k][i]==prev)continue;
            dfs1(v[k][i],k);
        }
    }
    else if(sum==1){
        rep(i,v[k].size()){
            if(v[k][i]==prev)continue;
            if(dp[v[k][i]])dp[k]=true;
            else dp[k]=false;
            dfs1(v[k][i],k);
        }
    }
    else{
        dp[k]=false;
        rep(i,v[k].size()){
            if(v[k][i]==prev)continue;
            dfs1(v[k][i],k);
        }
    }
    /*
    cout<<k<<"\n";
    debug(dp1);
    */
}
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> n;
    v.resize(n);
    dp.resize(n);
    dp1.resize(n);
    for (int i = 0; i < n-1; i++)
    {
        int temp,temp1;
        cin >> temp>>temp1;
        temp--;
        temp1--;
        v[temp].push_back(temp1);
        v[temp1].push_back(temp);
    }
    dfs(0,-1);
    //debug(dp);
    dfs1(0,-1);
    //debug(dp1);
    int count=0;
    rep(i,n){
        if(dp1[i])count++;
    }
    cout<<count<<"\n";
    rep(i,n){
        if(dp1[i]){
            cout<<i+1<<"\n";
        }
    }
}