#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;
}
