#include <stdio.h>
#include <stdlib.h>

int int_cmp(const int *a, const int *b)
{
	if (*a > *b)
		return 1;
	else if (*a < *b)
		return -1;
	else
		return 0;
}


int main(void)
{
	int n, q, c;
	int S[100000], T[50000];
	int i, j;


	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]);

	qsort(T, q, sizeof(int), (int (*)(const void *, const void *))int_cmp);

	c = 0;
	j = 0;
	for (i = 0; i < q; i++){
		while (T[i] > S[j] && j < n-1)
			j++;
		if (T[i] == S[j])
			c++;
	}

	printf("%d\n", c);
}