#include <bits/stdc++.h>
using namespace std;
void solve(){
int n, k; cin >> n >> k;
vector<vector<int>> adj(n);
set<pair<int,int>> uwu;
vector<int> cnt(n);
vector<int> vis(n, 0);
for(int i = 0; i < n; i++){
cin >> cnt[i]; uwu.insert({cnt[i], i});
adj[i] = vector<int>(cnt[i]);
for(auto &x : adj[i]) cin >> x;
sort(adj[i].begin(), adj[i].end()); //yeee
}
int ans = 1;
while(uwu.size()){
int i = uwu.begin()->second; vis[i] = 1;
uwu.erase(uwu.begin());
vector<int> clique = {i};
for(auto &x : adj[i]){
if(vis[x]) continue;
clique.push_back(x);
uwu.erase({cnt[x], x});
cnt[x]--;
uwu.insert({cnt[x], x});
}
int sz = clique.size();
vector<vector<int>> adj2(sz, vector<int>(sz, 0));
for(int i = 0; i < sz; i++){
for(int j = 0; j < sz; j++){
int i2 = clique[i];
int j2 = clique[j];
auto it = lower_bound(adj[i2].begin(), adj[i2].end(), j2);
if(it != adj[i2].end() && (*it) == j2) adj2[i][j] = 1;
}
}
vector<int> possible((1<<sz), 0);
vector<int> log2((1<<sz), 0);
for(int i = 0; i < sz; i++) log2[(1<<i)] = i;
for(int i = 0; i < (1<<sz); i++){
if(i==0){possible[i] = 1; continue;}
int lsb = (i&-i);
int j = i^lsb;
possible[i] = possible[j];
while(j){
int lsb2 = (j&-j);
possible[i] &= adj2[log2[lsb]][log2[lsb2]];
j ^= lsb2;
}
if(possible[i]) ans = max(ans, (int)__builtin_popcount(i));
}
}
cout<<ans<<endl;
}
signed main() {
cin.tie(0)->sync_with_stdio(0);
int t = 1;// cin >> t;
while(t--) solve();
}
