#include <stdio.h>
int main(void) {
	int n, q, t;
	int i, left, right, mid, count = 0;
	int s[10001];
	scanf("%d", &n);
	for (i = 0; i < n; i++)
		scanf("%d", &s[i]);
	scanf("%d", &q);
	for (i = 0; i < q; i++) {
		scanf("%d", &t);
		left = 0;
		right = n;
		while (left < right) {
			mid = (left + right) / 2;
			if (s[mid] == t) {
				count++;
				break;
			}
			else if (t < s[mid])
				right = mid;
			else
				left = mid + 1;
		}
	}
	printf("%d\n", count);
	return 0;
}