"""
 problem 1 from projecteuler.net

 Find the sum of all the numbers below 1000
 which are not multiples of 3 or 5.
 
"""

def divisible_by(a, b):
    """ Return True if a is divisible by b
        >>> divisible_by(10, 3)
        False
        >>> divisible_by(10, 2)
        True
    """
    return a % b == 0
    # this also works
    #if a % b == 0:
    #    return True
    #else:
    #    return False

def main():
    total = 0
    for i in range(1, 1000):  # 1 to 999
        if divisible_by(i, 3) or divisible_by(i,5):
            total = total + i
        ## this also works
        #if divisible_by(i, 3):
        #    total = total + i
        #elif divisible_by(i, 5):
        #    total = total + i
    print "The answer is ", total

if __name__ == "__main__":
    import doctest
    doctest.testmod()
    main()