#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
using namespace std;
#define int long long int
const int N = 5e3 + 10;
const int md = 1e9 + 7;
const int INF = 1e9;
struct Compare {
bool operator()(const pair<vector<int>, int>& a, const pair<vector<int>, int>& b) const {
return a.first.size() > b.first.size();
}
};
int32_t main(int32_t argc, char *argv[]) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int T = 1;
// cin >> T;
while (T--) {
int n, k;
cin >> n >> k;
vector<multiset<int>> a(n, multiset<int> ());
vector<vector<int>> b(n, vector<int> ());
// vector<vector<int>> mp(N, vector<int> (N));
for (int i = 0; i < n; i++) {
int d;
cin >> d;
while (d--) {
int x;
cin >> x;
// mp[i][x] = 1;
a[i].insert(x);
b[i].push_back(x);
}
}
set<pair<vector<int>, int>, Compare> q;
int ans = 0;
vector<int> e;
for (int w = 0; w < n; w++) {
if (w >= 0) {
map<int, bool> vs;
q.insert(make_pair(e, w));
while (!q.empty()) {
auto [v, u] = *q.begin();
ans = max(ans, (int) v.size() + 1);
// cout << u << '\n';
// for (auto r : v)
// cout << r << " ";
// cout << '\n';
q.erase(q.begin());
for (auto i : b[u]) {
auto v1 = v;
bool ok = 1;
for (auto j : v) {
if (a[i].find(j) == a[i].end()) {
ok = 0;
break;
}
}
if (ok && !vs[i]) {
v1.push_back(u);
q.insert(make_pair(v1, i));
}
}
vs[u] = 1;
}
}
}
cout << ans << '\n';
}
return 0;
}
