[BOJ] 11375. 열혈강호

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
	static ArrayList<Integer>[] graph;
	static boolean[] v;
	static int[] match;
	public static void main(String[] args) {
		int answer = 0;
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int M = sc.nextInt();
		
		graph = new ArrayList[N+1];
		
		v = new boolean[M+1];		
		match = new int[M+1];
		
		for(int i = 1; i <= N; i++) {
			graph[i] = new ArrayList<>();
		}
					
		for(int i = 1; i <= N; i++) {			
			int k = sc.nextInt();
			for(int j = 0; j < k; j++) {
				int a  = sc.nextInt();
				graph[i].add(a);
			}
		}
							
		for(int i = 1; i <= N; i++) {
			Arrays.fill(v, false);
			if(matching(i)) answer++;
		}
				
		System.out.println(answer);
	}
	
	public static boolean matching(int num) {
        for(int target : graph[num]) {
            if(v[target]) continue;
            v[target] = true;

            if(match[target] == 0 || matching(match[target])) {
                match[target] = num;
                return true;
            }
        }		
		
		return false;
	}
}