BalticOI2017 Political Development

//CAN'T FORGET
//CAN'T FORGET
//CAN'T FORGET

//#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;
#define _ 0
const int maxn=1e6+5;
const int inf=0x3f3f3f3f;
inline int read()
{
	int x=0,f=1;
	char ch=getchar();
	while(ch<'0'||ch>'9')
	{
		if(ch=='-')
			f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9')
	{
		x=(x<<1)+(x<<3)+(ch^48);
		ch=getchar();
	}
	return x*f;
}
struct node{
	int to,nxt;
}edge[maxn];
int head[maxn],tot;
void addedge(int u,int v)
{
	edge[++tot].to=v;
	edge[tot].nxt=head[u];
	head[u]=tot;
}
int n,k,dgr[maxn];
vector<int> stk,stk1;
unordered_map<int,int> vis[maxn];
int vis1[maxn],cnt,ans;
bool check()
{
	for(int i=stk1.size()-1;i>=0;i--)
		for(int j=i-1;j>=0;j--)
			if(vis[stk1[i]].find(stk1[j])==vis[stk1[i]].end())
				return false;
	return true;
}
void solve(int x)
{
	stk.clear();
	for(int i=head[x];i;i=edge[i].nxt)
	{
		int y=edge[i].to;
		if(vis1[y])
			continue;
		stk.push_back(y);
	}
	int sz=stk.size();
	for(int i=0;i<(1<<sz);i++)
	{
		if(__builtin_popcount(i)+1<=ans)
			continue;
		stk1.clear();
		stk1.push_back(x);
		for(int j=0;j<sz;j++)
			if((i>>j)&1)
				stk1.push_back(stk[j]);
		if(check())
			ans=stk1.size();
	}
	return ;
}
queue<int> q;
void bfs()
{
	for(int i=0;i<n;i++)
		if(dgr[i]<k)
			q.push(i);
	while(!q.empty())
	{
		int x=q.front();
		q.pop();
		solve(x);
		vis1[x]=1;
		for(int i=head[x];i;i=edge[i].nxt)
		{
			int y=edge[i].to;
			dgr[y]--;
			if(dgr[y]==k-1)
				q.push(y);
		}
	}
	return ;
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
//	freopen("poldev.in","r",stdin);
//	freopen("poldev.out","w",stdout);
    cin>>n>>k;
    for(int i=0;i<n;i++)
    {
    	cin>>dgr[i];
    	for(int j=1;j<=dgr[i];j++)
    	{
    		int x;
    		cin>>x;
    		addedge(x,i);
    		vis[i][x]=1;
	}
    }
    bfs();
    cout<<ans<<endl;
    return ~~(0^_^0);
}
/*
Notes:
1.看所有题目
2.注意数据范围
3.想想自己还能做什么而不是做了什么
4.看清题目!!!
5.记得把调试代码删掉!!!!
6.longlong时 1要写成1ll
7.Think twice code once, think once code forever!
*/