public class Main {
    public static void main(String[ ] args) {

        int age = 19;

        if (age < 21) {
            throw new ArithmeticException("Sorry - We only sell to customers 21 years old and above!");
        }
        else {
            System.out.println("Order accepted!");
        }
    }
}
// Output: Exception in thread "main" java.lang.ArithmeticException: Sorry - We only sell to customers 21 years old and above!
//	at org.example.Main.main(Main.java:12)