[백준] 4158번 CD (silver 5

import java.io.*;
import java.util.*;

public class Main{
    public static void main(String[] args) throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
        HashMap<Integer, Integer> dict = new HashMap<>();

        //믄제 제대로 읽기 여러 케이스
        while(true) {
            dict.clear();
            StringTokenizer st = new StringTokenizer(br.readLine());
            int n = Integer.valueOf(st.nextToken());
            int m = Integer.valueOf(st.nextToken());
            if(n+m==0){
                break;
            }
            int answer = 0;
            for (int i = 0; i < n; i++) {
                dict.put(Integer.valueOf(br.readLine()), 1);
            }
            for (int j = 0; j < m; j++) {
                if (dict.get(Integer.valueOf(br.readLine())) != null) {
                    answer += 1;
                }
            }
            bw.write(answer + "\n");
        }
        bw.flush();
    }
}