using System;

public class Program

{

    public static void Main()

    {

        int age = int.Parse(Console.ReadLine());

        double wm = double.Parse(Console.ReadLine());

        int toyPrice = int.Parse(Console.ReadLine());

        int yearMoney = 0;

        double balance = 0;

        for(int i = 1; i <= age; i++){

            if(i % 2 == 0){

                yearMoney += 10;

                balance += yearMoney - 1;

            }

            else balance += toyPrice;

        }

        if(wm <= balance) Console.WriteLine($"Yes! {balance-wm:f2}");

        else Console.WriteLine($"No! {wm-balance:f2}");

    }

}