interface IPayment {
	void pay();
}

abstract class Payment implements IPayment {
	public Payment() {
		initialize();
	}

	protected abstract void initialize();
}

class PaytmPayment extends Payment{
	public PaytmPayment() {
		super();
	}

	@Override
	protected void initialize() {
		// setup with paytm server
		System.out.println("paytm server initialized");
	}

	@Override
	public void pay() {
		System.out.println("pay by paytm");
	}

}

class GooglePayPayment extends Payment {
	public GooglePayPayment() {
		super();
	}

	@Override
	protected void initialize() {
		// setup with paytm server
		System.out.println("googlepay server initialized");
	}

	@Override
	public void pay() {
		System.out.println("pay by googlepay");
	}

}

class PaypalPayment extends Payment {
	public PaypalPayment() {
		super();
	}

	@Override
	protected void initialize() {
		// setup with paytm server
		System.out.println("paypal server initialized");
	}

	@Override
	public void pay() {
		System.out.println("pay by paypal");
	}

}