#include <bits/stdc++.h>
#define int int64_t
using namespace std;
constexpr int MAXN = 50009;
set <int> g[MAXN];
vector <int> d;
int ans = 1;
int n, k;
void dfs(int v, set <int> vv) {
if(d[v] < (int)vv.size()) return;
for(auto j : vv) {
if( !g[ v ].count( j ) ) {return;}
}
vv.insert(v);
if((int)vv.size() == k) {
cout << k;
exit(0);
}
ans = max(ans, (int)vv.size() );
for(auto to : g[v]) {
if( !vv.count( to ) ) {
dfs(to, vv);
}
}
}
void solve() {
cin >> n >> k;
d.resize(n + 1);
for(int i = 1; i <= n; i++ ){
cin >> d[i];
for(int j = 0; j < d[i]; j++) {
int x;
cin >> x;
x++;
g[ i ].insert(x);
}
}
set<int> emp;
for(int i = 1; i <= n; i++) {
dfs(i, emp);
}
cout << ans;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
//freopen("7-router.in", "r", stdin);
//freopen("7-router.out.txt", "w", stdout);
int tt = 1;
//cin >> tt;
while (tt--){
solve();
}
}
