ROT13 Cipher Transformation

The problem requires you to implement a ROT13 cipher transformation. In ROT13, each lowercase letter from 'a' to 'z' is replaced by the letter 13 positions after it in the alphabet. If the transformation goes past 'z', it wraps around to the beginning of the alphabet.

Formally, for a lowercase letter \(x\), the transformation is defined as:
\[ rot13(x) = \begin{cases} \text{chr}(((\text{ord}(x) - \text{ord}('a') + 13) \mod 26) + \text{ord}('a')) & \text{if } x \in [a, z] \\ x & \text{otherwise} \end{cases} \]

Any character that is not a lowercase letter remains unchanged. For example, if the input is "hello", the output should be "uryyb".

inputFormat

The input consists of a single line containing the string to transform. The string may include lowercase letters, digits, spaces, and punctuation.

outputFormat

Output the transformed string after applying the ROT13 cipher to the input.

hello

uryyb