负值场景需要处理

input_val=input().split(" ")
price=float(input_val[0])
month,day,discount=map(int,input_val[1:])
if month==11 and day==11:
    price=price*0.7
elif month==12 and day==12:
    price=price*0.8
if discount==1:
    price=price-50
if price<0:
    price=0
print("{:.2f}".format(price))