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

	int main(){
    int i,count=0;
	int left=0,right,mid,ans=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++){
		right = n;
	while(left < right){
	mid = (left + right)/2;
	if(T[i] == A[mid]){
		count = 1;
		break;
	}

	if(T[i] > A[mid])left = mid+1;
	else if(T[i] < A[mid])right = mid;
		     }
    
    if(count == 1)ans++;
					
		}

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

	return 0;
	}