#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;
vector<pll> cliq_masks[10];
bool used[50'001];
vi graph[50'001];
unordered_set<int> set_graph[50'001];
int deg[50'001];
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//random_start();
int n,k;
cin >> n >> k;
rep2(z,1,9)
{
map<pii,int> ind_map;
int cur = 0;
rep(i,z)
{
rep2(j,i+1,z-1)
{
ind_map[{i,j}] = cur++;
}
}
rep(mask,(1 << z))
{
ll m = 0;
vi verts;
rep(i,z)
{
verts.pb(z);
}
forall(it,verts)
{
forall(it2,verts)
{
if(it >= it2) continue;
m |= (1LL << (ll)ind_map[{it,it2}]);
}
}
cliq_masks[z].pb({m,count_bits(mask)});
}
}
rep(i,n)
{
cin >> deg[i];
rep(j,deg[i])
{
int x;
cin >> x;
graph[i].pb(x);
set_graph[i].insert(x);
}
}
priority_queue<pii,vector<pii>,greater<pii>> pq;
ll ans = 0;
rep(i,n) pq.push({deg[i],i});
while(!pq.empty())
{
pii t = pq.top();
pq.pop();
if(used[t.ss] || t.ff >= k) continue;
used[t.ss] = 1;
vi verts;
forall(it,graph[t.ss])
{
if(!used[it])
{
verts.pb(it);
deg[it]--;
pq.push({deg[it],it});
}
}
ll edge_mask = 0;
ll cur = 0;
forall(it,verts)
{
forall(it2,verts)
{
if(it >= it2) continue;
if(set_graph[it].find(it2) != set_graph[it].end())
{
edge_mask |= (1LL << cur);
}
cur++;
}
}
forall(it,cliq_masks[siz(verts)])
{
if((edge_mask & it.ff) == it.ff)
{
ans = max(ans,it.ss+1);
}
}
}
cout << ans << "\n";
}
