#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define fi first
#define se second
const int MX = 2e5 + 10;
int N, K, vis[MX], sz[MX]; map<pii, int> mp;
vector<int> adj[MX];
priority_queue<pii, vector<pii>, greater<pii>> pq;
int solve(int x){
vector<int> kew;
for(int nx : adj[x]){
if(vis[nx]) continue;
kew.push_back(nx);
}
int ns = kew.size(), mk = 1 << ns, ans = 0;
for(int mask = 0; mask < mk; mask++){
int num = 1;
bool curr = true;
for(int j = 0; j < ns; j++){
if((mask >> j & 1) != 1) continue;
num++;
if(!mp[make_pair(x, kew[j])]){
curr = false;
break;
}
for(int k = j + 1; k < ns; k++){
if((mask >> k & 1) != 1) continue;
if(!mp[make_pair(kew[k], kew[j])]){
curr = false;
break;
}
}
}
if(curr) ans = max(ans, num);
}
return ans;
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> N >> K;
for(int i = 0; i < N; i++){
int v; cin >> sz[i];
for(int j = 0; j < sz[i]; j++){
cin >> v;
adj[i].push_back(v);
mp[make_pair(i, v)] = 1;
}
}
for(int i = 0; i < N; i++) pq.push({sz[i], i});
int mx = 1;
for(;!pq.empty();){
int curr = pq.top().se; pq.pop();
if(vis[curr]) continue;
mx = max(mx, solve(curr));
vis[curr] = 1;
for(int nx : adj[curr]){
if(!vis[nx]){
sz[nx]--;
pq.push({sz[nx], nx});
}
}
}
cout << mx << '\n';
}
