#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(void)
{
	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;
}


