import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		int n = scanner.nextInt();
		int[] sArray = new int[n];
		for (int i = 0; i < n; i++) {
			sArray[i] = scanner.nextInt();
		}
		int p = scanner.nextInt();
		int[] tArray = new int[p];
		int cnt = 0;
		for (int i = 0; i < p; i++) {
			tArray[i] = scanner.nextInt();
			if(binarySearch(sArray, tArray[i], 0, n-1)){
				cnt++;
			}
		}
		System.out.println(cnt);
	}
	
	public static boolean binarySearch(int[] sArray, int tElement, int start,
			int end) {

		if (tElement == sArray[(start + end) / 2]) {
			return true;
		} else if (start == end) {
			return false;
		} else {
			if (tElement < sArray[(start + end) / 2]) {
				return binarySearch(sArray, tElement, start,
						(start + end) / 2);
			} else {
				return binarySearch(sArray, tElement, (start + end) / 2+1, end);
			}
		}
	}
}
/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