#include <bits/stdc++.h>
#define DIM 50010
using namespace std;
priority_queue <pair<int,int>, vector <pair<int,int> >, greater<pair<int,int> > > H;
set <int> L[DIM];
int n,k,i,j,sol,el,nod;
int v[DIM],x[DIM],viz[DIM],f[DIM],g[DIM];
int verif (int pas, int nod){
for (int i=1;i<pas;i++){
int vecin = x[i];
if (L[nod].find(vecin) == L[nod].end())
return 0;
if (L[vecin].find(nod) == L[vecin].end())
return 0;
}
return 1;
}
void back (int pas){
sol = max (sol,pas-1);
if (pas >= k)
return;
for (int i=1;i<=el;i++){
if (!f[i] && v[i] > x[pas-1] && verif(pas,v[i])){
x[pas] = v[i];
f[i] = 1;
back(pas+1);
f[i] = 0;
}
}
}
void get_max_clique (int nod){
el = 0;
for (auto vecin:L[nod])
v[++el] = vecin;
sort (v+1,v+el+1);
back (1);
}
int main (){
//ifstream cin ("date.in");
//ofstream cout ("date.out");
cin>>n>>k;
for (i=1;i<=n;i++){
cin>>g[i];
for (j=1;j<=g[i];j++){
cin>>nod;
L[i].insert(nod+1);
}
H.push (make_pair(g[i],i));
}
while (!H.empty()){
int nod = H.top().second;
int grad = H.top().first;
H.pop();
if (grad != g[nod]) /// inseamna ca nu e ala cu gradul minim
continue;
/// vreau sa gasesc clica maxima din care poate face parte nod
get_max_clique (nod);
viz[nod] = 1;
/// acum il elimin pe nod si toate muchiile
for (auto vecin:L[nod]){
g[vecin]--;
L[vecin].erase(L[vecin].find(nod));
if (!viz[vecin]){ /// nu am incercat sa obtin clica de aici deloc
viz[vecin] = 1;
H.push(make_pair(g[vecin],vecin));
}
}
L[nod].clear();
}
cout<<sol+1;
return 0;
}
