import java.util.Arrays;
import java.util.Scanner;
public class Main {
	
	static boolean search(int[] S,int a,int b,int target){
		if(a<=b){
			if(S[(a+b)/2]==target){
				return true;
			}else if(S[(a+b)/2]<target){
				return search(S,((a+b)/2)+1,b,target);
			}else{
				return search(S,a,((a+b)/2)-1,target);
			}
		}else{
			return false;
		}
	}
	
	public static void main(String[] args) {
		Scanner scan=new Scanner(System.in);
		int n=scan.nextInt();
		int S[]=new int[n];
		for(int i=0;i<n;i++){
			S[i]=scan.nextInt();
		}
		Arrays.sort(S);
		int q=scan.nextInt();
		int count=0;
		int x;
		for(int i=0;i<q;i++){
			x=scan.nextInt();
			if(search(S,0,n-1,x)){
				count++;
			}
		}
		System.out.println(count);
		scan.close();
	}

}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz