atm.py

def atm():
    CHARGE = 0.5
    temp = input()
    temp = temp.split()
    withdrawal = int(temp[0])
    balance = float(temp[1])

    if ((withdrawal <= balance) and (withdrawal%5 == 0)):
        balance -= withdrawal+CHARGE 
             
    else:
        balance = balance

    print ('%0.2f' %balance)

atm()