lili2

import java.util.Scanner;

public class lilid {



    public static void main(String[] args){

        Scanner scan = new Scanner(System.in);

        int age = Integer.parseInt(scan.nextLine());
        double priceOfWashingMachine = Double.parseDouble(scan.nextLine());
        int presentPrice = Integer.parseInt(scan.nextLine());

        int numberOfToys = 0;
        int savedMoney = 0;
        int moneyForBirthday = 10;

        for (int currentYear = 1; currentYear <= age; currentYear++) {
            if(currentYear % 2 == 0){
                savedMoney += (moneyForBirthday - 1);
                moneyForBirthday += 10;


            } else {


                numberOfToys++;

            }
        }

        savedMoney += numberOfToys * presentPrice;

        System.out.println((savedMoney >= priceOfWashingMachine?

                String.format("Yes! %.2f", (savedMoney - priceOfWashingMachine))
                : String.format("No! %.2f", (priceOfWashingMachine - savedMoney))));


    }
}