#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(),v.rend()
#define pb push_back
#define sz(a) (int)a.size()
const int N = 5e4 + 10;
unordered_set<int> st[N];
vector<int> adj[N];
set<int> aaa[N];
int ans = 1;
void solve() {
int n, k; cin >> n >> k;
queue<int> q;
vector<bool> pushed(n, false);
for(int i = 0; i < n; ++i) {
int x; cin >> x;
if(x >= 1) {
for(int j = 0; j < x; ++j) {
int bl; cin >> bl;
aaa[i].insert(bl);
st[i].insert(bl);
}
}
if(x < k) {
q.push(i);
pushed[i] = true;
}
}
while(!q.empty()) {
int i = q.front();
q.pop();
for(auto x: aaa[i]) adj[i].pb(x);
vector<int> dp(1 << (sz(adj[i])), 0);
dp[0] = 1;
for(int mask = 0; mask < (1 << (sz(adj[i]))); ++mask) {
if(!dp[mask]) continue;
int cnt = 1;
for(int f = 0; f < sz(adj[i]); ++f) {
if(mask >> f & 1) ++cnt;
}
ans = max(ans, cnt);
for(int j = 0; j < sz(adj[i]); ++j) {
if(mask >> j & 1) continue;
bool check = true;
for(int f = 0; f < sz(adj[i]); ++f) {
if(mask >> f & 1) {
if(st[adj[i][j]].find(adj[i][f]) == st[adj[i][j]].end()) check = false;
}
}
if(check) dp[mask | (1 << j)] = 1;
}
}
for(auto f: adj[i]) {
aaa[f].erase(i);
if(sz(aaa[f]) < k && !pushed[f]) {
pushed[f] = true;
q.push(f);
}
}
}
cout << ans << "\n";
}
int32_t main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int t = 1;
//cin >> t;
while(t--) {
solve();
}
}
