how can I get a specific data on a map in java? [closed]

Hello, how can I take a specific value within a map? by means of a set ??

            do {
                Student s = new Student();

                s.setListName(numerolista2);
                System.out.println("ingrese su nombre:");
                String name = sc.nextLine();
                s.setName(name);
                System.out.println("calificacion");

                int grade = sc.nextInt();
                s.setGrade(grade);
                sc.nextLine();
                map.put(numerolista2, s);

                System.out.println("deseas calificar mas alumnos: ");
                repetir = sc.nextInt();
                sc.nextLine();

            } while (repetir == 1);

            break;

        }