Zeller's Algorithm (no error checking) - Python

# MIT OCW 6.189
# Zeller's Algorithm
# July 12, 2013
# This program will determine the day of the week of any given date,
# past, present or future.

f_name = raw_input(str("What is your first name? "))
print "Enter your date of birth"
month, day, year = int(input("Month (1-12) :")), int(input("Day :")), int(raw_input("Year :"))
if month <= 2:
    a, new_year = month + 10, year -1
else:
    a, new_year = month - 2, year

b, c, d = day, new_year % 100, new_year / 100
#print "a = %s, b = %s, c = %s, d = %s, new_year = %s" % (a, b, c, d, new_year)
w, x, y = (13*a -1) / 5, c/4, d/4,
z = w+x+y+b+c-2*d
R = z%7
weekdays = ("Sunday", "Monday", "Tuesday", "Wednesday",
            "Thursday", "Friday", "Saturday")

print "The date %s/%s/%s falls on a %s" % (month, day, year, weekdays[R])