#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;
	
}

