#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

int N;
vi G[100005];
int W[100005], T[100005];

void f(int u, int p) {
    int sm = 0;
    each(v, G[u]) if (v != p) {
        f(v, u);
        sm -= W[v];
    }
    W[u] = max(sm + 1, 0);
}

void g(int u, int p, int xp) {
    smax(T[u], W[u] + xp);
    int sm = 0;
    each(v, G[u])if (v != p)sm += W[v];

    each(v, G[u])if (v != p) {
        int nxp = max(0, xp + 1 - (sm - W[v]));
        g(v, u, -nxp);
    }
}

void solve() {
    cin >> N;
    rep(i, N - 1) {
        int a, b;
        cin >> a >> b;
        --a; --b;
        G[a].push_back(b);
        G[b].push_back(a);
    }

    f(0, -1);
    g(0, -1, 0);

    vi ans;
    rep(i, N) {
        if (T[i] >= 1)ans.push_back(i + 1);
    }
    cout << sz(ans) << endl;
    each(x, ans)cout << x << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);
    solve();
    return 0;
}