XORNUBER - Editorial

@darkshadows @atulshanbhag
what did u meant u said bit tricks can be used to check if the number is of the form 2^k - 1

please help me to find error in this problem.
Here is my sol https://www.codechef.com/viewsolution/11201858

guys help me to find error .Here is my sol https://www.codechef.com/viewsolution/11202138

This tricky case was extremely tricky. Couldn’t have found out without this Editorial. Awesome.