# Largest Series Product

Given a string of digits, calculate the largest product for a contiguous
substring of digits of length n.

For example, for the input `'1027839564'`, the largest product for a
series of 3 digits is 270 (9 * 5 * 6), and the largest product for a
series of 5 digits is 7560 (7 * 8 * 3 * 9 * 5).

Note that these series are only required to occupy *adjacent positions*
in the input; the digits need not be *numerically consecutive*.

For the input `'73167176531330624919225119674426574742355349194934'`,
the largest product for a series of 6 digits is 23520.


## Source

A variation on Problem 8 at Project Euler [http://projecteuler.net/problem=8](http://projecteuler.net/problem=8)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.