#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 = min+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;
}