import java.util.*;

public class HistoryExam {



    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        List<Integer> professorsList = new ArrayList<Integer>();
        for (int i = 0; i < a; i++) {
            professorsList.add(sc.nextInt());
        }

        int b = sc.nextInt();


        int counter = 0;

        for (int i = 0; i < b; i++) {
            int c = sc.nextInt();
            if (Collections.binarySearch(professorsList, c)>=0) {
                counter++;


            }
        }
        sc.close();
        System.out.println(counter);
    }
}