// gets sub1+sub2
#include <bits/stdc++.h>
using namespace std;
#define vb vector<bool>
#define vi vector<int>
#define vvi vector<vi>
#define sz(x) (int) (x).size()
#define all(x) (x).begin(), (x).end()
#define F0R(i, n) for (int i = 0; i < (n); ++i)
#define tiii tuple<int,int,int>
#define vtiii vector<tiii>
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int N, K;
cin >> N >> K;
vector<set<int>> adj(N);
vi d(N);
vb active(N, true);
queue<int> q;
F0R(i, N) {
int u;
cin >> d[i];
F0R(j, d[i]) cin >> u, adj[i].insert(u);
if (d[i] < K) q.push(i);
}
int res = 1;
while (!q.empty()) {
int v = q.front();
q.pop();
if (!active[v]) continue;
vi neig;
for (int u: adj[v]) {
if (active[u]) {
neig.push_back(u);
}
}
vi bm(sz(neig));
for (int i = 0; i < sz(neig); ++i) {
bm[i] = 1 << i;
for (int j = 0; j < sz(neig); ++j) {
if (adj[neig[i]].find(neig[j]) != adj[neig[i]].end()) {
bm[i] |= 1 << j;
}
}
}
for (int sel = 0; sel < (1 << sz(neig)); ++sel) {
int m = sel;
for (int i = 0; i < sz(neig); ++i) {
if ((sel & (1 << i)) > 0) {
m &= bm[i];
}
}
res = max(res, __builtin_popcount(m) + 1);
}
active[v] = false;
for (int u: neig) {
--d[u];
if (d[u] < K) q.push(u);
}
}
cout << res << endl;
}
