#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;
}