#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ldb;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ldb,ldb> pdd;
#define ff(i,a,b) for(int i = a; i <= b; i++)
#define fb(i,b,a) for(int i = b; i >= a; i--)
#define trav(a,x) for (auto& a : x)
#define sz(a) (int)(a).size()
#define fi first
#define se second
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k) print the k-th smallest number in os(0-based)
const int mod = 1000000007;
const int inf = 1e9 + 5;
const int mxN = 50005;
int n, K;
vector<int> g[mxN];
int deg[mxN];
bool los[mxN];
int dp[(1 << 11)];
int msk[(1 << 11)];
int main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> K;
map<pii,bool> ima;
ff(i,1,n){
int len;
cin >> len;
ff(j,1,len){
int X;
cin >> X; X++;
g[i].pb(X); deg[i] += 1;
ima[{i, X}] = ima[{X, i}] = 1;
}
}
set<pii> s;
ff(i,1,n)s.insert({deg[i], i});
int rez = 0;
while(sz(s)){
pii X = *s.begin(); s.erase(X); deg[X.se] = 0;
vector<int> vec; vec.pb(X.se);
for(auto c : g[X.se]){
if(deg[c] > 0){
vec.pb(c);
}
}
int L = sz(vec); // assert(L <= 10);
ff(i,0,L - 1){
msk[(1 << i)] = (1 << i);
ff(j,0,L - 1){
if(ima.count({vec[i], vec[j]}) == 1){
msk[(1 << i)] |= (1 << j);
}
}
}
dp[0] = (1 << L) - 1;
ff(mask,1,(1 << L) - 1){
int j = mask & (-mask);
dp[mask] = dp[mask ^ j] & msk[j];
}
ff(mask,1,(1 << L) - 1){
if((dp[mask] & mask) == mask){
rez = max(rez, __builtin_popcount(mask));
}
}
ff(i,1,L - 1){
int A = vec[i];
s.erase({deg[A], A});
deg[A] -= 1;
if(deg[A] > 0)s.insert({deg[A], A});
}
}
cout << rez << '\n';
return 0;
}
/*
5 3
2 1 2
3 0 2 3
3 0 1 4
2 1 4
2 2 3
// probati bojenje sahovski
*/
