#include <iostream>
#include <vector>
#include <set>
using namespace std;
using vi = vector<int>;
using pii = pair<int, int>;
#define sz(x) int(x.size())
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int N, K;
cin >> N >> K;
set<int> edge[N];
set<pii> people;
for(int i = 0; i < N; i++)
{
int D;
cin >> D;
people.insert({D, i});
for(int j = 0; j < D; j++)
{
int k;
cin >> k;
edge[i].insert(k);
}
}
int res = 1;
// cerr << "check\n";
vi getlog(100'000, 0);
for(int i = 0; i < 15; i++)
getlog[(1<<i)] = i;
for(int t = 0; t < N; t++)
{
// cerr << "t = " << t << '\n';
int u = people.begin()->second;
people.erase(people.begin());
// cerr << "u = " << u << '\n';
vi currpeople{u};
for(int v : edge[u])
{
currpeople.push_back(v);
}
int h = sz(currpeople);
vi conn(h, 0);
for(int i = 0; i < h; i++)
{
for(int j = i+1; j < h; j++)
{
if(edge[currpeople[i]].find(currpeople[j]) != edge[currpeople[i]].end())
{
conn[i] |= (1<<j);
conn[j] |= (1<<i);
}
}
}
// cerr << "done\n";
vi clique((1<<h), 0);
for(int s = 1; s < (1<<h); s++)
{
int ss = s&-s;
int rs = s - ss;
if((conn[getlog[ss]] & rs) == rs)
clique[s] = clique[rs] + 1;
res = max(res, clique[s]);
}
for(int v : edge[u])
{
people.erase({sz(edge[v]), v});
edge[v].erase(u);
people.insert({sz(edge[v]), v});
}
}
cout << res << '\n';
}
