import java.util.Scanner;

public class Expression {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int age = Integer.parseInt(scanner.nextLine());
        double priceWashingMachine = Double.parseDouble(scanner.nextLine());
        int priceForDoll = Integer.parseInt(scanner.nextLine()); //6
        double moneyPresent = 10;
        double numberDolls = 0;
        double moneyFromAllPresents = 0;
        int count = 0;

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

            if (i % 2 == 0){

                moneyFromAllPresents = moneyFromAllPresents + moneyPresent;
                moneyPresent = moneyPresent +10;
                count++;
            }
            else {
                numberDolls = numberDolls +1;
            }
        }
        moneyFromAllPresents = moneyPresent - count;
        double moneyFromDolls = priceForDoll * numberDolls;

        double allMoney = moneyFromAllPresents + moneyFromDolls;
        if ( allMoney > priceWashingMachine){
            allMoney = allMoney - priceWashingMachine;
            System.out.printf("yes!  %.2f",allMoney);
        }
        if ( allMoney < priceWashingMachine){
            allMoney = priceWashingMachine -allMoney;
            System.out.printf("No! + %.2f",allMoney);
        }
    }
}