#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <climits>
#include <cstring>
#include <cassert>


using namespace std;
//using namespace atcoder;

#define REP(i, n) for (int i=0; i<(n); ++i)
#define RREP(i, n) for (int i=(int)(n)-1; i>=0; --i)
#define FOR(i, a, n) for (int i=(a); i<(n); ++i)
#define RFOR(i, a, n) for (int i=(int)(n)-1; i>=(a); --i)

#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()

#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl
#define DEBUG(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<<endl;

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    os << "[";
    REP(i, SZ(v)) {
        if (i) os << ", ";
        os << v[i];
    }
    return os << "]";
}

template<class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    return os << "(" << p.first << " " << p.second << ")";
}

template<class T>
bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmin(T &a, const T &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;
using vvi = vector<vi>;
using vvll = vector<vll>;

const ll MOD = 1e9 + 7;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;
const ld eps = 1e-9;


// edit

template<typename E, typename O=E, typename F1=function<E(E, O)>, typename F2=function<E(E, E)>>
struct Rerooting {
    struct Edge {
        int to;
        int rev;
        O w;
    };

    vector<vector<Edge>> graph;
    vector<vector<E>> dp;
    vector<vector<int>> vis;

    const int N;
    const E ie; // 要素の単位元
    const F1 f1;
    const F2 f2;


    Rerooting(int N, E ie, F1 f1, F2 f2) : graph(N), dp(N), vis(N), N(N), ie(ie), f1(f1), f2(f2) {
    }

    // 重みとかがない場合でもwに適当な値を入れておくこと
    void add_edge(int u, int v, O w) {
        int su = graph[u].size();
        int sv = graph[v].size();

        graph[u].push_back({v, sv, w});
        graph[v].push_back({u, su, w});
    }

    // 根をrとしたときrのc番目の子の値を求める
    E dfs_sub(int r, int c) {
        if (vis[r][c]) return dp[r][c];
        vis[r][c] = true;

        E &ret = dp[r][c];

        int u = graph[r][c].to;
        int su = graph[u].size();

        // TODO
        //葉に対する例外処理　
        if (graph[u].size() == 1) {
            ret = 1;
            return ret;
        }

        bool win_exist = false;
        for (int i = 0; i < su; ++i) {
            int v = graph[u][i].to;
            if (v == r) continue;

            E sub_res = dfs_sub(u, i);

            // TODO
//            ret = f2(ret, f1(sub_res, graph[u][i].w));
            if (sub_res) {
                win_exist = true;
            }
        }

        // TODO 問題によってはここで処理が生じる
        // 例: TDPC-V
        ret = !win_exist;

        return ret;
    }

    void dfs_all(int u, int p = -1) {
        int su = graph[u].size();
        vector<E> es(su + 2, 0);
        vector<E> lce(su + 2, 0);
        vector<E> rce(su + 2, 0);

        for (int i = 0; i < su; ++i) {
            // TODO
            es[i + 1] = lce[i + 1] = rce[i + 1] = dfs_sub(u, i);
        }

        for (int i = 0; i <= su; ++i) {
//            lce[i + 1] = f2(lce[i], lce[i + 1]);
            lce[i + 1] = lce[i] || lce[i + 1];
        }

        for (int i = su + 1; i > 0; --i) {
//            rce[i - 1] = f2(rce[i], rce[i - 1]);
            rce[i - 1] = rce[i] || rce[i - 1];
        }

        for (int i = 0; i < su; ++i) {
            // vが根のときのuに関する値を求める
            int v = graph[u][i].to;
            int rev = graph[u][i].rev;
            vis[v][rev] = true;

            // TODO
            // uが葉の場合の例外処理
            if (graph[u].size() == 1) {
                dp[v][rev] = 1;
                continue;
            }

            // TODO
//            dp[v][rev] = f2(lce[i], rce[i + 2]);
            dp[v][rev] = !(lce[i] || rce[i + 2]);

        }

        for (int i = 0; i < su; ++i) {
            int v = graph[u][i].to;
            if (v == p) continue;
            dfs_all(v, u);
        }
    }

    vector<E> build(int root = 0) {
        // dp, visの初期化
        for (int i = 0; i < N; ++i) {
            dp[i].resize(graph[i].size(), ie);
            vis[i].resize(graph[i].size(), false);
        }

        dfs_all(root, -1);

        vector<E> ret(N, ie);

        for (int u = 0; u < N; ++u) {
            int su = graph[u].size();
            bool win_exist = false;
            for (int i = 0; i < su; ++i) {
                // 部分問題を求める
                E sub_res = dfs_sub(u, i);

                // TODO
                // 部分問題の結果に作用素を作用させる
//                E applied_res = f1(sub_res, graph[u][i].w);

                // TODO
//                ret[u] = f2(ret[u], applied_res);
                if (sub_res) win_exist = true;
            }
            ret[u] = !win_exist;
        }

        return ret;
    }
};


void solve() {
    int N;
    cin >> N;

    using E = int;
    using O = int;
    E ie = -1;
    using F1 = function<void(E, O)>;
    using F2 = function<void(E, E)>;
    F1 f1 = [](E e, O o) -> void {
    };
    F2 f2 = [](E e1, E e2) -> void {
    };

    Rerooting<E, O, F1, F2> rr(N + 1, ie, f1, f2);
    REP(i, N - 1) {
        int a, b;
        cin >> a >> b;
        rr.add_edge(a, b, 0);
    }

    auto res = rr.build(1);
    vector<int> win_node;
    FOR(i, 1, N + 1) {
        if (res[i]) {
            win_node.push_back(i);
        }
    }
    cout << win_node.size() << endl;
    for (auto node: win_node) {
        cout << node << endl;
    }
}


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
//    std::ifstream in("input.txt");
//    std::cin.rdbuf(in.rdbuf());

    solve();


    return 0;
}