String Letter Reversal

A Python function that reverses string letters, leaving the order of digits intact.

Write a function `solution()`, that takes a string of alphabetic characters and digits and returns a new string with all letters reversed while maintaining the order of the digits intact. ### Parameters - `txt` (str): The input string which contains both alphabetic characters and digits. ### Returns - The function returns a string. The returned string is a transformation of the input string where all alphabetic characters are reversed, and the order of the digits is preserved. ### Examples ```python # The expected output is: "cb89a" solution("ab89c") ``` ```python # The expected output is: "onm5lk923j" solution("jkl5mn923o") ``` ```python # Since the string has no letters to reverse, it is returned as it is: "123a45" solution("123a45") ```