old_contents: import re
  input_data = re.split('\s',raw_input())
  
  bank_charge = 0.50
  
  withdraw_amount = int(input_data[0])
  bank_balance = float(input_data[1])
  
  debit_amount = withdraw_amount + bank_charge
  
  if withdraw_amount%5==0 and debit_amount <= bank_balance:
    bank_balance -= debit_amount
  
  print ("%.2f" % bank_balance)
  
  exit(0)
new_contents: import re
  input_data = re.split('\s',raw_input())
  
  bank_transaction_charge = 0.50
  
  withdraw_amount = int(input_data[0])
  bank_balance = float(input_data[1])
  
  debit_amount = withdraw_amount + bank_transaction_charge
  
  if withdraw_amount%5==0 and debit_amount <= bank_balance:
    bank_balance -= debit_amount
  
  print ("%.2f" % bank_balance)
  
  exit(0)
subject: Rename bank_charge to bank_transaction_charge