import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        MyScanner sc = new MyScanner();

        int n = sc.nextInt();
        int[] s = new int[n];
        for (int i = 0; i < n; i++) {
            s[i] = sc.nextInt();
        }

        int ans = 0;
        int q = sc.nextInt();
        for (int i = 0; i < q; i++) {
            int t = sc.nextInt();
            if (binarySearch(s, n, t) >= 0)
                ans++;
        }

        System.out.println(ans);
    }


    // 二分探索
    static int binarySearch(int[] a, int n, int key) {
        int left = 0;
        int right = n;
        while (left < right) {
            int mid = (left + right) / 2;
            if (a[mid] == key)
                return mid;
            else if (a[mid] < key)
                left = mid + 1;
            else
                right = mid;
        }
        return -1;
    }

    static class MyScanner {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 1 << 15);
        StringTokenizer tokenizer;

        String next() {
            try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            }
            return tokenizer.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }
    }
}

/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