const int LG = 21;
const int N = 400030;
const long long MOD = 998244353;
const long long INF = 1e9;
const long long INFLL = 1e18;
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<vector<int> > vvi;
typedef vector<ll> vll;
#define forn(i, n) for (int (i) = 0; (i) != (n); (i)++)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define popcount(x) __builtin_popcount(x)
#define popcountll(x) __builtin_popcountll(x)
#define fi first
#define se second
#define re return
#define pb push_back
#define uniq(x) sort(all(x)); (x).resize(unique(all(x)) - (x).begin())
#ifdef LOCAL
#define dbg(x) cerr << __LINE__ << " " << #x << " " << x << endl
#define ln cerr << __LINE__ << endl
#else
#define dbg(x) void(0)
#define ln void(0)
#endif // LOCAL
int cx[4] = {-1, 0, 1, 0};
int cy[4] = {0, -1, 0, 1};
string Yes[2] = {"No", "Yes"};
string YES[2] = {"NO", "YES"};
ll inq(ll x, ll y)
{
if (!y) re 1 % MOD;
ll l = inq(x, y / 2);
if (y % 2) re l * l % MOD * x % MOD;
re l * l % MOD;
}
ll rev(ll x)
{
return inq(x, MOD - 2);
}
bool __precomputed_combinatorics = 0;
vector<ll> __fact, __ufact, __rev;
void __precompute_combinatorics()
{
__precomputed_combinatorics = 1;
__fact.resize(N);
__ufact.resize(N);
__rev.resize(N);
__rev[1] = 1;
for (int i = 2; i < N; i++) __rev[i] = MOD - __rev[MOD % i] * (MOD / i) % MOD;
__fact[0] = 1, __ufact[0] = 1;
for (int i = 1; i < N; i++) __fact[i] = __fact[i - 1] * i % MOD, __ufact[i] = __ufact[i - 1] * __rev[i] % MOD;
}
ll fact(int x)
{
if (!__precomputed_combinatorics) __precompute_combinatorics();
return __fact[x];
}
ll cnk(int n, int k)
{
if (k < 0 || k > n) return 0;
if (!__precomputed_combinatorics) __precompute_combinatorics();
return __fact[n] * __ufact[n - k] % MOD * __ufact[k] % MOD;
}
int Root(int x, vector<int> &root)
{
if (x == root[x]) return x;
return root[x] = Root(root[x], root);
}
void Merge(int v, int u, vector<int> &root, vector<int> &sz)
{
v = Root(v, root), u = Root(u, root);
if (v == u) return;
if (sz[v] < sz[u])
{
sz[u] += sz[v];
root[v] = u;
}
else
{
sz[v] += sz[u];
root[u] = v;
}
}
int ok(int x, int n)
{
return 0 <= x && x < n;
}
void bfs(int v, vi &dist, vector<vi> &graph)
{
fill(all(dist), -1);
dist[v] = 0;
vi q = {v};
for (int i = 0; i < q.size(); i++)
{
for (auto u : graph[q[i]])
{
if (dist[u] == -1)
{
dist[u] = dist[q[i]] + 1;
q.push_back(u);
}
}
}
}
vector<int> z_func(string &s)
{
vector<int> z(s.size());
z[0] = s.size();
int L = 0, R = 0;
for (int i = 1; i < s.size(); i++)
{
z[i] = max(0, min(z[i - L], R - i));
while (i + z[i] < s.size() && s[i + z[i]] == s[z[i]]) z[i]++;
if (i + z[i] > R)
{
R = i + z[i];
L = i;
}
}
return z;
}
vector<int> p_func(string &s)
{
vector<int> p(s.size());
for (int i = 1; i < s.size(); i++)
{
int j = p[i - 1];
while (j > 0 && s[i] != s[j])
j = p[j - 1];
if (s[i] == s[j])
j++;
p[i] = j;
}
return p;
}
vector<int> d1_func(string &s)
{
vector<int> d1(s.size());
int L = 0, R = -1;
for (int i = 0; i < s.size(); i++)
{
int k = 0;
if (i <= R) k = min(R - i + 1, d1[R - i + L]);
while (i + k < s.size() && i - k >= 0 && s[i - k] == s[i + k])
k++;
d1[i] = k--;
if (i + k > R)
{
L = i - k;
R = i + k;
}
}
return d1;
}
vector<int> d2_func(string &s)
{
vector<int> d2(s.size());
int L = 0, R = -1;
for (int i = 1; i < s.size(); i++)
{
int k = 0;
if (i <= R) k = min(R - i + 1, d2[R - i + L + 1]);
while (i + k < s.size() && i - k - 1 >= 0 && s[i - k - 1] == s[i + k])
k++;
d2[i] = k--;
if (i + k > R)
{
L = i - k - 1;
R = i + k;
}
}
return d2;
}
ll log10(ll x)
{
if (x < 10) re 1;
re 1 + log10(x / 10);
}
ll ds(ll x)
{
if (x < 10) return x;
re x % 10 + ds(x / 10);
}
double sqr(double x)
{
return x * x;
}
bool in(int bit, int mask)
{
return (mask & (1 << bit)) > 0;
}
void Del(vector<int> &v, int pos)
{
swap(v[pos], v[v.size() - 1]);
v.pop_back();
}
long long g(vector<long long> &p, int pos)
{
if (ok(pos, p.size())) return p[pos];
if (pos < 0 || p.size() == 0) return 0;
return p.back();
}
int g(vector<int> &p, int pos)
{
if (ok(pos, p.size())) return p[pos];
if (pos < 0 || p.size() == 0) return 0;
return p.back();
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n, k;
cin >> n >> k;
vector<vector<int> > graph(n);
map<pii, int> mm;
forn(i, n)
{
int s;
cin >> s;
forn(j, s)
{
int a;
cin >> a;
graph[i].push_back(a);
mm[{i, a}] = 1;
}
}
set<pair<int, int> > deg_act;
vector<int> isact(n, 1);
vector<int> deg(n, 1);
for (int i = 0; i < n; i++)
{
deg_act.insert({graph[i].size(), i});
deg[i] = graph[i].size();
}
int ans = 1;
while (deg_act.size())
{
vector<int> V;
auto it = deg_act.begin();
while (1)
{
if (it == deg_act.end()) break;
pii x = *it;
if (x.first != (*deg_act.begin()).first) break;
V.push_back(x.second);
it++;
}
for (auto x : V)
{
vector<int> v;
for (auto u : graph[x])
{
if (isact[u])
v.push_back(u);
}
assert(v.size() <= k);
forn(mask, (1 << v.size()))
{
if (popcount(mask) + 1 < ans) continue;
int t = 1;
for (int i = 0; t && i < v.size(); i++) for (int j = i + 1; t && j < v.size(); j++) if (in(i, mask) && in(j, mask))
{
if (mm[{v[i], v[j]}] == 0) t = 0;
break;
}
if (t) ans = max(ans, popcount(mask) + 1);
}
}
for (auto x : V)
{
isact[x] = 0;
deg_act.erase({deg[x], x});
for (auto u : graph[x])
{
if (isact[u])
{
deg_act.erase({deg[u], u});
deg[u]--;
deg_act.insert({deg[u], u});
}
}
}
}
cout << ans;
}
/* Note:
Check constants at the beginning of the code.
N is set to 4e5 but be careful in problems with large constant factor.
Setting N in every problem is more effective.
Check corner cases.
N = 1
No def int long long for now.
Add something here.
*/
