#include<stdio.h>
int A[1000000],n;
int search(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(search(k))sum++;
	}
	printf("%d\n",sum);
	
	return 0;
}
