import java.util.*;

class Main {

	static Scanner in = new Scanner(System.in);

    void solve() {
		int n = in.nextInt();
		int[] s = new int[n];
		for(int i = 0; i < n; i++) s[i] = in.nextInt();
		int q = in.nextInt();
		int[] t = new int[q];
		for(int i = 0; i < q; i++) t[i] = in.nextInt();
		int ans = 0;
		for(int i : t) if(serch(s, i) > 0) ans++;
		System.out.println(ans);
	}

	int serch(int[] a, int n){
		int left = 0;
		int right = a.length;
		int mid = -1;
		while(left < right){
			mid = (left + right) / 2;
			if(a[mid] == n) return 1;
			else if(n > a[mid]) left = mid + 1;
			else if(n < a[mid]) right = mid;
		}
		return 0;
	}

    public static void main(String[] args) {
        new Main().solve();
    }
}
/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