# Instructions

An [Armstrong number][armstrong-number] is a number that is the sum of its own digits each raised to the power of the number of digits.

For example:

- 9 is an Armstrong number, because `9 = 9^1 = 9`
- 10 is _not_ an Armstrong number, because `10 != 1^2 + 0^2 = 1`
- 153 is an Armstrong number, because: `153 = 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153`
- 154 is _not_ an Armstrong number, because: `154 != 1^3 + 5^3 + 4^3 = 1 + 125 + 64 = 190`

Write some code to determine whether a number is an Armstrong number.

[armstrong-number]: https://en.wikipedia.org/wiki/Narcissistic_number
