#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(void){
	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;

}
