import unittest, string


def adjacent_digits_product(numb_str, digits_count):
    cases = len(numb_str) - digits_count
    biggest = 1
    for i in range(cases):
        product = 1
        for e in range(i, i+digits_count):
            product *= int(numb_str[e])
        if product > biggest:
            biggest = product
    return biggest

NUMB = """
73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450
"""
NUMB = string.replace(NUMB[:], '\n', '')

class AdjacentProductTestCase(unittest.TestCase):

    def test_4_digits(self):
        self.assertEqual(adjacent_digits_product(NUMB, 4), 5832)

    def test_5_digits(self):
        self.assertEqual(adjacent_digits_product(NUMB, 5), 40824)

    def test_13_digits(self):
        self.assertEqual(adjacent_digits_product(NUMB, 13), 23514624000)

    def test_17_digits(self):
        self.assertEqual(adjacent_digits_product(NUMB, 17), 5292994896000L)

    def test_25_digits(self):
        self.assertEqual(adjacent_digits_product(NUMB, 25), 94810963968000000L)

    def test_50_digits(self):
        self.assertEqual(adjacent_digits_product(NUMB, 50), 71245459770757226566778880000000L)