private void action() {
			String s1 = "";

			StringBuilder sb = new StringBuilder();
			Iterator<String> iterator = students.keySet().iterator();

			Student student, tStudent;

			//build list to reverse
			ArrayList<Student> studentsToSort = new ArrayList<Student>();

			while (iterator.hasNext()) {
				student = students.get(iterator.next());
				tStudent = new Student(student.getNumber());
				tStudent.addScore(student.getBestScore());
				studentsToSort.add(tStudent);
			}

			//must be reverse
			Collections.sort(studentsToSort,Collections.reverseOrder(new Student("")));

			//output just reversed list
			Iterator<Student> si = studentsToSort.iterator();
			while (si.hasNext()) {
				tStudent = si.next();
				sb.append(tStudent.getNumber())
					.append("-")
					.append(tStudent.getBestScore())
					.append("\n");
			}

			s1 = sb.toString();
			System.out.println(s1);
		}