The Perfect Stall

/*
ID: modengd1
PROG: stall4
LANG: C++
*/
#include <iostream>
#include <stdio.h>
#include <memory.h>
#include <vector>
#include <queue>
using namespace std;
#define INF 0x7fffffff
struct edge
{
    int to,cap,rev;
};
vector<edge> G[402];
int level[402];
int iter[402];
void add_edge(int from,int to,int cap)
{
    G[from].push_back(edge{to,cap,G[to].size()});
    G[to].push_back(edge{from,0,G[from].size()-1});
}

int DFS(int v,int t,int f)
{
    if(v==t)
        return f;
    for(int &i=iter[v];i<G[v].size();i++)
    {
        edge &e=G[v][i];
        if(e.cap>0&&level[v]<level[e.to])
        {
            int d=DFS(e.to,t,min(f,e.cap));
            if(d>0)
            {
                e.cap-=d;
                G[e.to][e.rev].cap+=d;
                return d;
            }
        }
    }
    return 0;
}
void BFS(int S)
{
    memset(level,-1,sizeof(level));
    queue<int > que;
    level[S]=0;
    que.push(S);
    while(!que.empty())
    {
        int v = que.front(); que.pop();
        for(int i=0;i<G[v].size();i++)
        {
            edge &e=G[v][i];
            if(e.cap>0&&level[e.to] < 0)
            {
                level[e.to] = level[v]+1;
                que.push(e.to);
            }
        }
    }
}
int max_flow(int s,int t)
{
    int flow=0;
    while(true)
    {
        BFS(s);
        if(level[t]<0)
            return flow;
        memset(iter,0,sizeof(iter));
        int f;
        while((f=DFS(s,t,INF))>0)
        {
            flow+=f;
        }
    }
}
int main()
{
    freopen("stall4.in","r",stdin);
    freopen("stall4.out","w",stdout);
    int M,N,a,b,c;
    scanf("%d%d",&N,&M);
    for(int i=1;i<=N;i++)
    {
        add_edge(0,i,1);
        scanf("%d",&a);
        for(int j=0;j<a;j++)
        {
            scanf("%d",&b);
            add_edge(i,N+b,1);
        }
    }
    for(int i=1;i<=M;i++)
        add_edge(N+i,N+M+1,1);
    cout<<max_flow(0,N+M+1)<<endl;
    return 0;
}