Mine

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


class Main {
	public static void main(String args[]) throws NumberFormatException, IOException {
		ArrayList<Integer> answer = new ArrayList<Integer>();
		ArrayList<Integer> a = new ArrayList<Integer>();
		Scanner sc = new Scanner(System.in);
		int jack = 0, jill = 0;
		int num = 0;
		int index = 0;
		BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
		String[] s = input.readLine().split(" ");
		jack = Integer.parseInt(s[0]);
		jill = Integer.parseInt(s[1]);
		while (true) {
			if(jack==0&&jill==0)
				break;
			a = new ArrayList<Integer>();
			int m = 0;
			num = 0;
			index = 0;
			for (int i = 0; i < jack; i++) {
				index = Integer.parseInt(input.readLine());
				a.add(index);
			}
			for (int j = 0; j < jill; j++) {
				index = Integer.parseInt(input.readLine());
				if (m < jack && a.get(m) == index) {
					num++;
					m++;
					continue;
				}
				while (m < jack && a.get(m) < index) {
					m++;
				}
				if (m < jack && a.get(m) == index) {
					num++;
					m++;
					continue;
				}
			}
			answer.add(num);
			s = input.readLine().split(" ");
			jack = Integer.parseInt(s[0]);
			jill = Integer.parseInt(s[1]);
		}
		for (int i = 0; i < answer.size(); i++)
			System.out.println(answer.get(i));
	}
}