static void displayMenu() {
        System.out.println("COMMAND MENU");
        System.out.println("print   - Print all element of array");
        System.out.println("sum1    - Sum of munber old");
        System.out.println("sum2    - Sum of munber divisibility 5");
        System.out.println("sum3    - Sum prime number");
        System.out.println("help    - Show this menu");
        System.out.println("exit    - Exit this application\n");
    }