class CustomException extends Exception {

  public CustomException(String message) {
    super(message);
  }
}

public class Pr3b {

  public static void main(String args[]) {
    try {
      int age = -20;
      if (age < 0) {
        throw new CustomException("Age can't be negtive.");
      }
      System.out.println("Aeg:" + age);
    } catch (CustomException e) {
      System.err.println("Error:" + e.getMessage());
    }
  }
}