#include <stdio.h>

int A[100000];


int binarysearch(int key,int n){
	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,n,q,key,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",&key);
		if(binarysearch(key,n) == 1) sum++;
	}
	
	printf("%d\n",sum);
		
return 0;
}

