import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class madeInPrevMonth {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.println("Insert number of orders in the current month:");
        int n = Integer.parseInt(scanner.nextLine());

        List<String> emailsCurrentMonth = new ArrayList<>();

        System.out.println("Insert emails of customers:");
        while(n-- > 0){
            String emailCurrentMonth = scanner.nextLine();
            emailsCurrentMonth.add(emailCurrentMonth);
        }

        System.out.println("Insert number of orders in the prev month:");
        int m = Integer.parseInt(scanner.nextLine());

        List<String> emailsPrevMonth = new ArrayList<>();

        System.out.println("Insert emails of customers:");
        while(m-- > 0){
            String emailPrevMonth = scanner.nextLine();
            emailsPrevMonth.add(emailPrevMonth);
        }


        List<String> emailsOccur = new ArrayList<>();

        if (emailsCurrentMonth.size() >= emailsPrevMonth.size()) {
            for (int i = 0; i < emailsCurrentMonth.size(); i++) {
                for (int j = 0; j < emailsPrevMonth.size(); j++) {
                    if (emailsCurrentMonth.get(i).equals(emailsPrevMonth.get(j))){
                        emailsOccur.add(emailsCurrentMonth.get(i));
                    }
                }
            }
        } else {
            for (int i = 0; i < emailsPrevMonth.size(); i++) {
                for (int j = 0; j < emailsCurrentMonth.size(); j++) {
                    if(emailsPrevMonth.get(i).equals(emailsCurrentMonth.get(j))){
                        emailsOccur.add(emailsPrevMonth.get(i));
                    }
                }
            }
        }

        List<String> emailCounter = new ArrayList<>();

        for (int i = 0; i < emailsOccur.size(); i++) {
            if(!emailCounter.contains(emailsOccur.get(i))){
                emailCounter.add(emailsOccur.get(i));
            }
        }

        System.out.println();
        System.out.println("Users made order in this and prev month = " + emailCounter.size());
    }
}