#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; ll tot = 0;
for(int i = 0; i < N; i++){
int x,y; cin >> x; tot+=x;
while(x--){
cin>>y; //if(y<x) continue;
adj[i].pb(y),edge[i][y]=1;
}
}
if(!tot){
cout << 1 << '\n';
return 0;
}
int ans = 1;
for(int i = 0; i < N; i++){
for(int j = 0; j < sz(adj[i]); j++){
int num = (edge[adj[i][j]]&edge[i]).count();
if(num>=1){
cout << 3 << "\n"; return 0;
}
}
}
cout << 2 << "\n";
}
