#include <stdio.h>

#define N 100000;
#define Q 50000;

int BinarySearch(int,int);

int S[N];

int main()
{
	int n,q,T[Q],i,c = 0;
	
	scanf("%d",&n);
	
	for(i = 0; i < n; i++){
		scanf("%d",&S[i]);
	}
	
	scanf("%d",&q);
	
	for(i = 0; i < q; i++){
		scanf("%d",&T[i]);
	
		c += BinarySearch(n,T[i]);
	
	}

	printf("%d",c);
	
	return 0;
}

int BinarySearch(n,key){
	int left = 0;
	int right = n;
	int mid;
	while(left < right){
		
		mid = (left + right) / 2;
	
		if(key == S[mid]) return 1;
	
		if(key > S[mid]) left = mid + 1;
	
		else if(key < S[mid]) right = mid;
	}
	return 0;
}
	