#include <bits/stdc++.h>
using namespace std;

#define rep(i, N) for (int i = 0; i < (N); i++)
#define all(a) (a).begin(), (a).end()
#define pb push_back

using ll = long long;
using i_i = tuple<int, int>;

void dfs_down(int u, int p, vector<vector<int>>& G, vector<bool>& down) {
    down[u] = true;
    for (int v: G[u]) if (v != p) {
        dfs_down(v, u, G, down);
        if (down[v]) down[u] = false;
    }
}

void dfs_up(int u, int p, vector<vector<int>>& G, vector<bool>& down, vector<bool>& up) {
    int cnt = up[u];
    for (int v: G[u]) if (v != p) cnt += down[v];
    for (int v: G[u]) if (v != p) {
        up[v] = (cnt - down[v] == 0);
        dfs_up(v, u, G, down, up);
    }
}

int main() {
    int N; cin >> N;
    vector<vector<int>> G(N);
    rep(i, N - 1) {
        int u, v;
        scanf("%d%d", &u, &v);
        u--; v--;
        G[u].pb(v);
        G[v].pb(u);
    }
    vector<bool> down(N);
    dfs_down(0, -1, G, down);
    vector<bool> up(N);
    dfs_up(0, -1, G, down, up);
    vector<int> V;
    rep(u, N) if (down[u] && !up[u]) V.pb(u);
    int M = V.size();
    cout << M << endl;
    rep(j, M) printf("%d\n", V[j] + 1);
    // rep(u, N) cout << down[u];
    // cout << endl;
    // rep(u, N) cout << up[u];
    // cout << endl;
}