Previous and next letter#8610
You are given a letter of the English alphabet ('A' < c < 'Z' or 'a' < c < 'z'), which may be uppercase or lowercase.
A single letter of the English alphabet ('A' < c < 'Z' or 'a' < c < 'z').
Print the letter that precedes , followed by the letter that comes after in the English alphabet, preserving the case.
Example 1
Example 2