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++) {
            if (binarySearch(S, T[i]) != -1) {
                count++;
            }
        }
        System.out.println(count);
    }

    private static int binarySearch(int[] /*sorted*/ array, int target) {
        int left = 0;
        int right = array.length;
        int mid;
        while (left < right) {
            mid = (left + right) / 2;
            if (array[mid] == target) {
                return mid;
            } else if (array[mid] > target) {
                right = mid;
            } else {
                left = mid + 1;
            }
        }
        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