#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;
}
