import java.util.Scanner;

public class Main {

	static int n;
	static int[] S;
	static int q;
	static int[] T;
	static int ans;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		S = new int[n];
		for (int i = 0; i < n; i++) {
			S[i] = sc.nextInt();
		}
		q = sc.nextInt();
		T = new int[q];
		for (int i = 0; i < q; i++) {
			T[i] = sc.nextInt();
		}
		sc.close();

		ans = 0;
		for (int i = 0; i < q; i++) {
			binarySearch(T[i]);
		}
		System.out.println(ans);
	}

	private static void binarySearch(int num) {
		int left = 0;
		int right = n;

		while (left < right) {
			int mid = (left + right) / 2;
			if (S[mid] == num) {
				ans++;
				return;
			} else if (S[mid] > num) {
				right = mid;
			} else if (S[mid] < num) {
				left = mid + 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