#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define all(x) x.begin(), x.end()
using namespace std;
template <class X, class Y> bool minimize(X &a, Y b) {
if (a > b) return a = b, true;
return false;
}
template <class X, class Y> bool maximize(X &a, Y b) {
if (a < b) return a = b, true;
return false;
}
const int N = 5e4 + 7;
int n, k;
int deg[N];
bool vis[N];
bool dp[1 << 10];
bool has_edge[11][11];
vector<int> node;
vector<int> adj[N];
signed main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> k;
priority_queue<pair<int, int>> heap;
for (int i = 1; i <= n; i ++) {
cin >> deg[i];
heap.emplace(- deg[i], i);
for (int j = 0; j < deg[i]; j ++) {
int u; cin >> u;
u ++;
adj[i].push_back(u);
}
sort(all(adj[i]));
}
auto calc = [&]() {
int m = node.size();
memset(has_edge, false, sizeof has_edge);
for (int i = 0; i < m; i ++) {
for (int j = 0; j < m; j ++) {
has_edge[i][j] = binary_search(all(adj[node[i]]), node[j]);
}
}
int res = 0;
dp[0] = true;
for (int mask = 1; mask < 1 << m; mask ++) {
int f = -1;
dp[mask] = true;
for (int i = 0; i < m; i ++) {
if (~mask >> i & 1) {
continue;
}
if (f == -1) {
f = i;
dp[mask] = dp[mask ^ (1 << i)];
} else {
dp[mask] &= has_edge[f][i];
}
}
if (dp[mask]) {
maximize(res, __builtin_popcount(mask));
}
}
return res;
};
int res = 0;
while (!heap.empty()) {
int u = heap.top().se;
heap.pop();
if (vis[u]) {
continue;
}
vis[u] = true;
node.clear();
for (int v: adj[u]) if (!vis[v]) {
deg[v] --;
heap.emplace(-deg[v], v);
node.push_back(v);
}
maximize(res, calc() + 1);
}
cout << res;
return 0;
}
