#include <stdio.h>

int i;

int binarySearch(int n, int A[], int key){
	int left, right, mid;
	left = 0;
	right = n;

	while (left < right){
		mid = (left + right)/2;
		if (key == A[mid])
			return mid;
		if (key > A[mid])
			left = mid + 1;
		else if( key < A[mid])
			right = mid;
	}
	return -1;
}


int main(void) {
	int n,q,j,count=0;
	
	scanf("%d",&n);
	int S[n];
	
	for(i=0; i<n; i++){
		scanf("%d",&S[i]);
	}
	
	scanf("%d",&q);
	int T[q];
	
	for(i=0; i<q; i++){
		scanf("%d",&T[i]);
		if (binarySearch(n,S,T[i])!=-1){
			count++;
		}
	}
	printf("%d\n",count);
	
	return 0;
}



