public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("What is your age?");

        while(scanner.hasNext()) {
            final String supposedAge = scanner.next();
            int age;
            {
                try {
                    age = Integer.valueOf(supposedAge);
                } catch (Exception ex) {
                    System.out.println("You must supply an integer for your age.");
                    System.exit(0);
                    return;
                }

                if(age > 120) {
                    System.out.println("You must supply a valid age.");
                    System.exit(0);
                    return;
                }

                if(age == 0) age++;
            }
            System.out.println("Your age is " + age + ".");
            if(age <= 2) {
                System.out.println("You are a newborn.");
            } else if(age < 6 && age > 2 ) {
                System.out.println("You are a toddler");
            } else if(age > 6 && age < 13) {
                System.out.println("You are a child");
            } else if(age >= 13 && age < 18) {
                System.out.println("You are a teenager.");
            } else {
                System.out.println("You are an adult.");
            }
            System.exit(1);
        }

    }