
import java.util.*;

class Main{
	public static void main(String[] args){
		Scanner in = new Scanner(System.in);
		int n = in.nextInt();
		int[] s = new int[n];
		for(int i=0;i<n;i++){
			s[i] = in.nextInt();
		}
		int q = in.nextInt();
		int[] t = new int[q];
		for(int i=0;i<q;i++){
			t[i] = in.nextInt();
		}
		int count = 0;
		for(int i=0;i<q;i++){
			int ul = s.length;
			int ll = -1;
			boolean flag = false;
			while(ll+1<ul){
				int mid = (ll+ul)/2;
				if(s[mid] == t[i]){
					flag = true;
					break;
				}
				else if(s[mid]<t[i]){
					ll = mid;
				}
				else{
					ul = mid;
				}
			}
			if(flag){
				count++;
			}
		}
		System.out.println(count);
	}
}
/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