#include <stdio.h>
#define MAX 10001

int S[MAX];
int T[500];

int binarySearch(int n,int key) {
	int left = 0;
	int right = n;
	int mid;
	
	while (left < right) {
		mid = (left + right) / 2;
		if (S[mid] == key) {
			return 1;
		} else if (key < S[mid]) {
			right = mid;
		} else {
			left = mid + 1;
		}
	}
	return 0;
}

int main(void)
{
	int n, i, j, q, cnt;
	
	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[i]);
	}

	cnt = 0;
	for (i = 0; i < q; ++i) {
		cnt += binarySearch(n, T[i]);
	}
	printf("%d\n", cnt);
	
	return 0;
}