CleverLily

import java.util.Scanner;

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

        int years = Integer.parseInt(scanner.nextLine());
        double preisWascher = Double.parseDouble(scanner.nextLine());
        int priceToy = Integer.parseInt(scanner.nextLine());

        int toyCounter = 0;
        int summonney = 0;
        int counterSum = 1;

        for (int i = 1; i <= years; i++) {
            if (i % 2 == 1) {
                toyCounter ++;
            }else {
                summonney += (10 * counterSum);
                counterSum ++;

            }
        }
        int priceAllToys = toyCounter * priceToy;
        int total = priceAllToys + (summonney - counterSum);
        if (preisWascher < (total + 1)) {
            System.out.printf("Yes! %.2f", (total + 1) - preisWascher);
        }else {
            System.out.printf("No! %.2f", preisWascher - (total + 1));
        }
    }
}