// Error.Java
class Error {
    public static class NestedError1 extends RuntimeException {
        public NestedError1(String cause) {
            super(String.format("runtime faii: %s", cause));
        }
    }
    public static class UnsupportedVersion extends IllegalArgumentException {
        public UnsupportedVersion(Exception err) {
            super("UnsupportedVersion", err);
        }
    }
}
 
// HelloWorld.java
class HelloWorld {
    public static void main(String[] args) throws Error.NestedError1 {
        int t = 1;
        if (t == 1) {
            throw new Error.UnsupportedVersion(new Exception("1.0 incomplitable with 1.2"));
        } else if (t == 2) {
            throw new Error.NestedError1("Wooohala");
        } else {
            System.out.println("Hello, World!"); 
        }
    }
}