# The four adjacent digits in the 1000-digit number that have the greatest product
# are 9 × 9 × 8 × 9 = 5832.
#
# Digit shown below
#
# Find the thirteen adjacent digits in the 1000-digit number that have the
# greatest product. What is the value of this product?

import re

class LargestNumber:
    main_string = re.sub('\s*\n*', '', """
        73167176531330624919225119674426574742355349194934
        96983520312774506326239578318016984801869478851843
        85861560789112949495459501737958331952853208805511
        12540698747158523863050715693290963295227443043557
        66896648950445244523161731856403098711121722383113
        62229893423380308135336276614282806444486645238749
        30358907296290491560440772390713810515859307960866
        70172427121883998797908792274921901699720888093776
        65727333001053367881220235421809751254540594752243
        52584907711670556013604839586446706324415722155397
        53697817977846174064955149290862569321978468622482
        83972241375657056057490261407972968652414535100474
        82166370484403199890008895243450658541227588666881
        16427171479924442928230863465674813919123162824586
        17866458359124566529476545682848912883142607690042
        24219022671055626321111109370544217506941658960408
        07198403850962455444362981230987879927244284909188
        84580156166097919133875499200524063689912560717606
        05886116467109405077541002256983155200055935729725
        71636269561882670428252483600823257530420752963450
    """)

    def __init__(self, count):
        self.count              = count
        self.current_products   = []

    def build_products(self):
        self.current_products = []
        for x in range(0, len(LargestNumber.main_string) - self.count):
            product = 1
            for y in LargestNumber.main_string[x:x+self.count:1]:
                product *= int(y)
            self.current_products.append(product)

    def max_product(self):
        if not self.current_products:
            self.build_products()
        return max(self.current_products)


l = LargestNumber(13)
print(l.max_product())
