# Exercise 3A
# Standardising surnames.
#
# Author: David Watt.

mc = "M'c"

def standardise (surname):
    "Return surname with the prefix 'Mc' or 'Mac' replaced by mc (above)."
    l = len(surname)
    if l > 2 and surname[0:2] == 'Mc':
        return mc + surname[2:]
    elif l > 3 and surname[0:3] == 'Mac':
        return mc + surname[3:]
    else:
        return surname

def compare (surname1, surname2):
    "Return -1 if surname1 should come before surname2, \
     or +1 if it should come after, or 0 if they are the same."
    s1 = standardise(surname1)
    s2 = standardise(surname2)
    if s1 == s2:
        return 0
    elif s1 < s2:
        return -1
    else:
        return 1