import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int[] S = new int[n];
        for (int i = 0; i < n; i++) {
            S[i] = scanner.nextInt();
        }
        int q = scanner.nextInt();
        int cnt = 0;
        for (int i = 0; i < q; i++) {
            if (binarySearch(S, scanner.nextInt()) != -1) {
                cnt++;
            }
        }
        System.out.println(cnt);
    }

    private static int binarySearch(int[] a, int key) {
        int lo = 0;
        int hi = a.length - 1;
        while (lo <= hi) {
            int mid = (lo + hi) / 2;
            if (a[mid] > key) {
                hi = mid - 1;
            } else if (a[mid] < key) {
                lo = mid + 1;
            } else {
                return mid;
            }
        }
        return -1;
    }
}
/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