import java.util.Scanner;

public class _1991 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a, b, i;

        a = sc.nextInt();

        int[] str = new int[a];
        for (i = 0; i < a; i++) {
            str[i] = sc.nextInt();
        }
        b = sc.nextInt();
        int counter = 0;
        for (i = 0; i < b; i++) {
            int c = sc.nextInt();
            for (int aStr : str) {
                if (aStr == c) {
                    counter++;
                }
            }
        }
        System.out.println(counter);
    }
}