/*:
 # Champernowne's constant
 [Problem 40](https://projecteuler.net/problem=40) - Difficulty level: 5%

 An irrational decimal fraction is created by concatenating the positive integers:

 ![](40-1.png)

 It can be seen that the 12th digit of the fractional part is 1.

 If d(n) represents the nth digit of the fractional part, find the value of the following expression.
 
 ![](40-2.png)

 */
