#include<stdio.h>
	int binarySearch(int);
	int n,q;
    int A[10000],T[10000];

int main(){
	int i,count=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",&T[i]);
	}

	for(i=0 ; i<q ; i++){
		count += binarySearch(T[i]);
	}

	printf("%d\n",count);

	return 0;
}

int binarySearch(int key){
	int left=0,right,mid;

	right = n;

	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;
	}