#include <stdio.h>
int main(){
	int n,s[10000],q,t[500],i,cnt=0,left=0,right,mid;
	
	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]);
	
	for(i=0;i<q;i++){
		right=n;
		while(left<right){
			mid=(left+right)/2;
			if(s[mid]==t[i]){
				cnt++;
				break;
			}
			else if(t[i]<s[mid]) right=mid;
			else left=mid+1;
		}
	}
	
	printf("%d\n",cnt);
	
	return 0;
}


