## 008 - paths across grid

See Problem 8: Find the greatest product of five consecutive digits in a 1000-digit number.

This is fairly straightforward. First we define the number, using Python's implicit string continuation:

numstr = '73167176531330624919225119674426574742355349194934' '96983520312774506326239578318016984801869478851843' '85861560789112949495459501737958331952853208805511' '12540698747158523863050715693290963295227443043557' '66896648950445244523161731856403098711121722383113' '62229893423380308135336276614282806444486645238749' '30358907296290491560440772390713810515859307960866' '70172427121883998797908792274921901699720888093776' '65727333001053367881220235421809751254540594752243' '52584907711670556013604839586446706324415722155397' '53697817977846174064955149290862569321978468622482' '83972241375657056057490261407972968652414535100474' '82166370484403199890008895243450658541227588666881' '16427171479924442928230863465674813919123162824586' '17866458359124566529476545682848912883142607690042' '24219022671055626321111109370544217506941658960408' '07198403850962455444362981230987879927244284909188' '84580156166097919133875499200524063689912560717606' '05886116467109405077541002256983155200055935729725' '71636269561882670428252483600823257530420752963450' …