sales

city_name = str(input())
sales_volume = float(input())
commission = 0
flag = False
if city_name == 'Sofia':
    if 0 <= sales_volume <= 500:
        commission = 0.05
    elif 500 < sales_volume <= 1000:
        commission = 0.07
    elif 1000 < sales_volume <= 10000:
        commission = 0.08
    elif sales_volume > 10000:
        commission = 0.12
    else:
        flag = True
elif city_name == 'Varna':
    if 0 <= sales_volume <= 500:
        commission = 0.045
    elif 500 < sales_volume <= 1000:
        commission = 0.075
    elif 1000 < sales_volume <= 10000:
        commission = 0.1
    elif sales_volume > 10000:
        commission = 0.13
    else:
        flag = True
elif city_name == 'Plovdiv':
    if 0 <= sales_volume <= 500:
        commission = 0.055
    elif 500 < sales_volume <= 1000:
        commission = 0.08
    elif 1000 < sales_volume <= 10000:
        commission = 0.12
    elif sales_volume > 10000:
        commission = 0.145
    else:
        flag = True
else:
    flag = True

if flag:
    print('error')
else:
    final_winning = sales_volume * commission
    print(f"{final_winning:.2f}")

""""""""""""""""""""""""""""""""""""""""""""""""""""""
city_name = str(input())
sales_volume = float(input())
commission = 0

if city_name == 'Sofia':
    if 0 <= sales_volume <= 500:
        commission = 0.05
    elif 500 < sales_volume <= 1000:
        commission = 0.07
    elif 1000 < sales_volume <= 10000:
        commission = 0.08
    elif sales_volume > 10000:
        commission = 0.12

elif city_name == 'Varna':
    if 0 <= sales_volume <= 500:
        commission = 0.045
    elif 500 < sales_volume <= 1000:
        commission = 0.075
    elif 1000 < sales_volume <= 10000:
        commission = 0.1
    elif sales_volume > 10000:
        commission = 0.13

elif city_name == 'Plovdiv':
    if 0 <= sales_volume <= 500:
        commission = 0.055
    elif 500 < sales_volume <= 1000:
        commission = 0.08
    elif 1000 < sales_volume <= 10000:
        commission = 0.12
    elif sales_volume > 10000:
        commission = 0.145

if commission == 0:
    print('error')
else:
    final_winning = sales_volume * commission
    print(f"{final_winning:.2f}")