#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;
}