Number is a palindrome if it is equal to the number with digits in reversed order.
For example, 5, 44, 171, 4884 are palindromes, and 43, 194, 4773 are not.
Write a function which takes a positive integer and returns the number of special steps needed to obtain a palindrome. The special step is: "reverse the digits, and add to the original number". If the resulting number is not a palindrome, repeat the procedure with the sum until the resulting number is a palindrome.
If the input number is already a palindrome, the number of steps is 0.
All inputs are guaranteed to have a final palindrome which does not overflow long.
For example, start with 87:
87 + 78 = 165 - step 1, not a palindrome
165 + 561 = 726 - step 2, not a palindrome
726 + 627 = 1353 - step 3, not a palindrome
1353 + 3531 = 4884 - step 4, palindrome!
4884 is a palindrome and we needed 4 steps to obtain it, so answer for 87 is 4.
Some interesting information on the problem can be found in this Wikipedia article on Lychrel numbers.