public class Main{
	public static void main(String[] args){
		General gen = new General();
		System.out.println(gen.currentDate());
		System.out.println(gen.name());
		System.out.println(gen.doMath());

		General gen2 = new Specification();
		System.out.println(gen2.currentDate());

		System.out.println(gen2.name());

		System.out.println(gen2.doMath());

	}
}

class General{
	Date currentDate(){
		return new Date;
	}

	String name(){
		return "Вася";
	}

	double doMath(){
		return 2+2;
	}
}


class Specification extends General{
	String name(){
		return "Петя";
	}
	double doMath(){
		return Math.PI;
	}
}