import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] S = new int[n]; 
		for (int i = 0; i < n; i++) {
			S[i] = sc.nextInt();
		}
		
		int q = sc.nextInt();
		int[] T = new int[q];
		for (int i = 0; i < q; i++) {
			T[i] = sc.nextInt();
		}
		
		int count = 0;
		for (int i = 0; i < T.length; i++) {
			int t = T[i];
			
			int l = -1;
			int u = S.length;
			while(u - l > 1) {
				int m = (u + l) / 2;	
				if(t == S[m]) { 
					count++;
					break;
				} else if (t < S[m]) {
					u = m;
				} else {
					l = m;
				}
			}
		}
		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