ages_lilly = int(input())
price_washingmashine = float(input())
one_toys_price = int(input())

money_for_presenet_lily = 0 #парите за всеки Ч РД
present_Lily_toys = 0
total_money = 0

for currenet_years in range (1, ages_lilly + 1):
    if currenet_years % 2 != 0:
        present_Lily_toys += 1

    else:
        money_for_presenet_lily += 10
        #brother_help -= 1
        total_money += money_for_presenet_lily - 1

#sum_sold_toys = present_Lily_toys * one_toys_price
#Savings_lily = money_for_presenet_lily + sum_sold_toys
total_money += present_Lily_toys * one_toys_price
#print(sum_sold_toys)
#print(Savings_lily)
diff = abs(total_money - price_washingmashine)
if total_money >= price_washingmashine:
    print(f"Yes! {diff:.2f}")
else:
    print(f"No! {diff:.2f}")