86

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

#define ll long long
const int N = 1001;
bool a[N][N];
int kq[N], d[N];
int n, k, dem;

void nhap() {
    cin >> n >> k; kq[1] = k;
    for (int i = 1; i <= n; ++i) {
        int m; cin >> m;
        for (int j = 1; j <= m; ++j) {
            int x; cin >> x;
            a[i][x] = true;
        }
    }
}

void dfs(int u) {
    d[u] = true;
    for (int v = 1; v <= n; ++v) {
        if (a[u][v] == 1 && d[v] == false) {
            kq[++dem] = v; d[v] = true;
            dfs(v);
        }
    }
}

void inKq() {
    cout << dem << endl;
    for (int j = 1; j <= dem; ++j)
        cout << kq[j] << ' ';
}

int main() {
    cin.tie(nullptr) -> sync_with_stdio(false);
    // freopen("ds.inp", "r", stdin);
    // freopen("ds.out", "w", stdout);

    nhap();
    dem = 1; dfs(k);
    inKq();
    return 0;
}