#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
using ll = long long;
using vi = vector<int>;
using ar2 = array<int,2>;
using ar3 = array<int,3>;
const int mxN = (int)5e4+10;
const int INF = (int)1e9+1;
const ll LINF = (ll)2e18+1;
const int MOD = (int)1e9+7;
int N, K;
vi adj[mxN];
bitset<mxN> edge[mxN];
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> N >> K;
for(int i = 0; i < N; i++){
int x,y; cin >> x;
while(x--){
cin>>y; if(y<x) continue;
adj[i].pb(y),edge[i][y]=edge[y][i]=1;
}
}
int ans = 1;
for(int i = 0; i < N; i++){
for(int mask = 0; mask < (1<<sz(adj[i])); mask++){
vi xd; int num = __builtin_popcount(mask);
if(ans>=num+1 or num+1>K) continue;
vi v; v.clear();
bool ok = 1; v.pb(i);
for(int j = 0; j < sz(adj[i]); j++){
if(mask>>j&1){
for(auto u : v)ok&=edge[u][adj[i][j]];
if(!ok) break;
v.pb(adj[i][j]);
}
}
if(ok) ans=num+1;
}
}
cout << ans << "\n";
}
