#include <bits/stdc++.h>
using namespace std;
//#pragma GCC optimize ("O3")
//#pragma GCC target ("sse4")
#define endl "\n"
typedef long long ll;
template<class T, class T2> inline ostream &operator <<(ostream &out, const pair<T, T2> &x) { out << x.first << " " << x.second; return out;}
template<class T, class T2> inline istream &operator >>(istream &in, pair<T, T2> &x) { in >> x.first >> x.second; return in;}
template<class T, class T2> inline bool chkmax(T &x, const T2 &y) { return x < y ? x = y, 1 : 0; }
template<class T, class T2> inline bool chkmin(T &x, const T2 &y) { return x > y ? x = y, 1 : 0; }
const ll mod = 1e9 + 7;
#ifndef LOCAL
#define cerr if(false) cerr
#endif
#define forn(N) for(int i = 0; i < (N); i ++)
#define forab(A, B) for(int i = (A); i < (B); i ++)
const int MAX_N = 1e5 + 10;
set<int> g[MAX_N];
int n, k;
const int MAX_K = 10;
bool adj[MAX_K][1 << MAX_K], can[1 << MAX_K];
int pw[MAX_N];
int solve() {
multiset<pair<int, int> > st;
forn(n) {
st.insert({g[i].size(), i});
}
auto rmEdge = [&st](int a, int b) {
st.erase({g[a].size(), a});
st.erase({g[b].size(), b});
g[a].erase(b);
g[b].erase(a);
if(g[a].size() != 0) {
st.insert({g[a].size(), a});
}
if(g[b].size() != 0) {
st.insert({g[b].size(), b});
}
};
auto getClique = [&st](int x) {
int sz = g[x].size();
vector<int> vert = {};
cerr << "from x " << x << ": ";
for(auto it : g[x]) {
vert.push_back(it);
cerr << it << " ";
}
cerr << endl;
forn(sz) {
fill(adj[i], adj[i] + (1 << sz), false);
adj[i][0] = true;
for(int mask = 1; mask < (1 << sz); mask ++) {
adj[i][mask] = adj[i][mask & (mask - 1)] & (g[vert[i]].find(vert[pw[mask - (mask & (mask - 1))]]) != g[vert[i]].end());
}
}
int ret = 0;
fill(can, can + (1 << sz), false);
can[0] = true;
forn(1 << sz) {
can[i] = can[i & (i - 1)] & adj[pw[i - (i & (i - 1))]][i & (i - 1)];
if(can[i]) {
chkmax(ret, __builtin_popcount(i));
}
}
return ret + 1;
};
int ret = 1;
while(!st.empty()) {
auto curr = st.begin(); st.erase(curr);
auto vert = (*curr).second;
cerr << "Trying vert " << vert << endl;
chkmax(ret, getClique(vert));
cerr << "Remove vert " << endl;
vector<int> toRem = {};
for(auto it : g[vert]) {toRem.push_back(it);}
for(auto it : toRem) {
rmEdge(vert, it);
}
}
return ret;
}
signed main() {
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
for(int i = 0, j = 1; i < MAX_K; i ++, j *= 2) {
pw[j] = i;
}
cin >> n >> k;
forn(n) {
int d;
cin >> d;
while(d --) {
int b;
cin >> b;
g[i].insert(b);
}
}
cout << solve() << endl;
return 0;
}
