#include <stdio.h>

int binarySearch(int *,int,int);

#define N 10000
#define Q 500
#define FOUND 1
#define NOT_FOUND 0

int main()
{
	int i,n,q,f,count=0,S[N],T[Q];

	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]);

	for(i = 0;i < q;i++)
	{
		f = binarySearch(S,T[i],n);
		count += f;
	}

	printf("%d\n",count);

	return 0;

}

int binarySearch(int *A,int key,int n)
{
	int left,right,mid;

	left = 0;
	right = n;

	while(left < right)
	{
		mid = (left + right) / 2;
		if(A[mid] == key)
			return FOUND;
		else if(key < A[mid])
			right = mid;
		else left = mid + 1;
	}
	
	return NOT_FOUND;
}