#include <bits/stdc++.h> using namespace std; int main() { int n, m; cin >> n >> m; int cnt[35] = {0}; for (int i = 0; i < n; i++) { int c; cin >> c; for (int j = 0; j < c; j++) { int x; cin >> x; cnt[x]++; } } int ans = 0; for (int i = 1; i <= m; i++) { if (cnt[i] == n) ans++; } cout << ans << endl; return 0; }