#include <stdio.h>

int A[1000000], n;

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

int main(int argc, char **argv) {
	int i, q, k, sum = 0;
	scanf("%d", &n);
	for (i = 0; i < n; i++) {
			scanf("%d",&A[i]);
	}
	scanf("%d", &q);
	for (i = 0; i < q; i++) {
		scanf("%d", &k);
		if (binarySearch(k))
			sum++;
	}
	printf("%d\n", sum);
	return 0;
}
