// Om Namah Shivaya
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a, b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a, b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
/*
*/
const int MOD = 1e9 + 7;
const int N = 5e4 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
vector<int> adj[N];
void solve(int test_case)
{
int n,k; cin >> n >> k;
rep(i,n){
int s; cin >> s;
rep(j,s){
int v; cin >> v;
adj[i].pb(v);
}
adj[i].pb(i);
sort(all(adj[i]));
}
int ans = 0;
rep(s,n){
auto nodes = adj[s];
int siz = sz(nodes);
vector<bool> dp(1<<siz);
dp[0] = 1;
rep1(mask,(1<<siz)-1){
vector<int> picked;
rep(i,siz){
if(mask & (1 << i)){
int u = nodes[i];
picked.pb(u);
}
}
int msb = -1;
rev(bit,siz-1,0){
if(mask & (1<<bit)){
msb = bit;
break;
}
}
int u = nodes[msb];
bool ok = true;
trav(v,picked){
if(!binary_search(all(adj[u]),v)){
ok = false;
break;
}
}
if(ok){
dp[mask] = dp[mask^(1<<msb)];
}
}
rep(mask,1<<siz){
if(dp[mask]){
int cnt = setbits(mask);
amax(ans,cnt);
}
}
}
cout << ans << endl;
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
