Program reading only the first number was entered, the rest of the number entered by the user program ignores and reading always the first number?

I have a program coding below, I tried but it is always reading the first number only in the cases....

"Program reading only the first number was entered, the rest of the number entered by the user program ignores and reading always the first number?" "Also please solve math.random for specific number only".

public static void main(String[] args) {

    Scanner reading = new Scanner(System.in);


    int randomNumber = (int) (Math.random() * 50-1);

    int input;
    int guessNumber;

    System.out.println("       Welcome UCT beginers Game we will tes your IQ      ");
    for (int i=1; i<3; i++)
    {
    System.out.println("       Please select your level Game     ");
    System.out.println("1. Three chances to play.");
    System.out.println("2. Five chances to play");
    System.out.println("3. Ten chances to play");
    System.out.println("4. Exit the Game");

    input = reading.nextInt();



    switch (input) 
    {

    case 1:
        System.out.println("       Welcome You have chosen level ONE. This is normally can pass only with higher IQ");
        System.out.println("Please Guess my number");
        guessNumber = reading.nextInt();
        if (randomNumber == guessNumber )
        {
            System.out.println("          Congratulation; You have earned 3 coins");
            break;

        }

        else if (randomNumber > guessNumber )
        {for (int a = 1; a < 3; a++)

            {
            System.out.println("          Sorry Low number");
            guessNumber = reading.nextInt();

            }
            System.out.println("Sorry!  we can't help you any more, You failed *** The number was "+randomNumber);
        }
        else if (randomNumber < guessNumber)
        {for (int a = 1; a < 3; a++)
            {
            System.out.println("          Sorry High number"     );
            guessNumber = reading.nextInt();
            }
            System.out.println("Sorry!  we can't help you any more, You failed *****The number was "+ randomNumber);
        }
        break;
    case 2:
        System.out.println("       Welcome You have chosen level TWO. This is normally can pass middale IQ");
        System.out.println("Please Guess my number");
        guessNumber = reading.nextInt();
        if (randomNumber == guessNumber )
        {
            System.out.println("          Congratulation; You have earned 3 coins");
            break;
        }
        else if (randomNumber > guessNumber )
        {for (int a = 1; a < 5; a++)
            {
            System.out.println("          Sorry Low number");
            guessNumber = reading.nextInt();
            }
        System.out.println("Sorry!  we can't help you any more, You failed *** The number was "+randomNumber);
        }
        else if (randomNumber < guessNumber)
        {for (int a = 1; a < 5; a++)
            {
            System.out.println("          Sorry High number");
            guessNumber = reading.nextInt();
            }
            System.out.println("Sorry!  we can't help you any more, You failed *** The number was"+randomNumber);
        }
        break;
    case 3:
        System.out.println("       Welcome You have chosen level THREE. This passes normally every person");
        System.out.println("Please Guess my number");
        guessNumber = reading.nextInt();
        if (randomNumber == guessNumber )
        {
            System.out.println("          Congratulation; You have earned 3 coins");
            break;
        }
        else if (randomNumber > guessNumber )
        {
            for (int a = 1; a < 10; a++)
            {
            System.out.println("          Sorry Low number");
            guessNumber = reading.nextInt();
            }
            System.out.println("Sorry!  we can't help you any more, You failed *** The number was "+randomNumber);
        }
        else if (randomNumber < guessNumber)
        {
            for (int a = 1; a < 10; a++)
            {
            System.out.println("          Sorry High number");
            guessNumber = reading.nextInt();
            }
            System.out.println("Sorry!  we can't help you any more, You failed *** The number was "+randomNumber);
        }
        break;
    case 4:

        System.exit(0);
        break;
    default:
        System.out.println("Invalid entary");
        break;

    }

}



}