#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef long double ld;
#define F first
#define S second
#define pb push_back
#define endl '\n'
#define Mp make_pair
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " = " << x << endl;
#define fast_io ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io freopen("input19.txt" , "r" , stdin) ;
const int N = 5e4+23, K=13;
vector<int> g[N];
int G[N], dp[1<<K];
int ind[N], deg[N];
int n, k;
int f(vector<int> vec){
sort(all(vec));
int n=vec.size();
for (int i=0; i<n; i++){
G[i]=0;
for (int u: g[vec[i]]){
int t=lower_bound(all(vec), u)-vec.begin();
if(t<vec.size() && vec[t]==u)G[i]|=(1<<t);
}
}
for (int mask=1; mask<(1<<n); mask++){
int k=__builtin_ctz(mask);
dp[mask]=max(dp[mask^(1<<k)], dp[mask&G[k]]+1);
}
return dp[(1<<n)-1];
}
int main()
{
fast_io
cin>>n>>k;
queue<int> q;
for (int i=0; i<n; i++){
cin>>deg[i];
for (int j=0; j<deg[i]; j++){
int u; cin>>u;
g[i].pb(u);
}
if(deg[i]<k) q.push(i);
}
int num=0;
while(!q.empty()){
int v=q.front();
q.pop();
ind[v]=num++;
for (int u: g[v]){
deg[u]--;
if(deg[u]==k-1) q.push(u);
}
}
int ans=1;
for (int v=0; v<n; v++){
vector<int> vec; vec.pb(v);
for (int u: g[v]) if(ind[v]<ind[u]) vec.pb(u);
ans=max(ans, f(vec));
}
cout<<ans<<endl;
}
