//9.    Часовник
public class MyClass {
    public static void main(String args[]) {
       int maxMinute = 59;
       int maxHour = 23;
       int currentHour = 0;
       while (currentHour <= maxHour) {
           for (int i = 0; i <= maxMinute; i++) {
               /* System.out.printf("%02d : %02d\n",currentHour,i); //proper solution */
               System.out.printf("%d : %d\n",currentHour,i); //needed softuni solution
           }
           currentHour++;
       }
    }
}