#include <stdio.h>          // printf(), scanf()
#include <stdlib.h>         // malloc(), free()
#include <string.h>         // memset()
#include <stdbool.h>

#define MAX_N 1000000000

int
main(int argc, char** argv)
{
	int n = 0;
	int q = 0;
	int t = 0;
	int i, j;
	bool* s = malloc(MAX_N);
	memset(s, 0x00, MAX_N);

	scanf("%d", &n);
	for (i = 0; i < n; ++i)
	{
		scanf("%d", &j);
		s[j] = true;
	}

	scanf("%d", &q);
	int count = 0;
	for (i = 0; i < q; ++i)
	{
		scanf("%d", &t);
		if (s[t])
			count++;
	}

	printf("%d\n", count);
	free(s);
	return 0;
}