import java.math.BigInteger;
import java.util.Objects;
import java.util.Set;

public class studfac {
	abstract class Person
	{
		protected String name;
		protected int ID;
		public boolean equals(Object ob) {
			if (ob == null || ob.getClass() != this.getClass()) return false;
			return this.ID == ((Person)ob).ID;
		}
		public int hashCode() {
			return Objects.hash(name, ID);
			//return name.hashCode() ^ ID;
		}
		abstract BigInteger getBalance();
	}
	class Course
	{
		Course(String newName, int newID)
		{
			name = newName;
			ID = newID;
		}
		public boolean equals(Object ob) {
			if (ob == null || ob.getClass() != this.getClass()) return false;
			return this.ID == ((Course)ob).ID;
		}
		public int hashCode() {
			return Objects.hash(name, ID);
			//return name.hashCode() ^ ID;
		}
		private String name;
		private int ID;
	}
	class Student extends Person
	{
		Student(String newName, int newID, Set<Course> newCourses)
		{
			name = newName;
			ID = newID;
			courses = newCourses;
		}
		private Set<Course> courses;

		@Override
		BigInteger getBalance() {
			return BigInteger.valueOf(courses.size() * -20);
		}
	}
	class FacultyMember extends Person
	{
		FacultyMember(String newName, int newID, Set<Course> newCourses)
		{
			name = newName;
			ID = newID;
			courses = newCourses;
		}
		private Set<Course> courses;

		@Override
		BigInteger getBalance() {
			return BigInteger.valueOf(courses.size() * 30);
		}
	}
	public static void main(String [] args)
	{
	
	}
}