#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 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;
}
