<p>Given a palindromic string of lowercase English letters <code>palindrome</code>, replace <strong>exactly one</strong> character with any lowercase English letter so that the resulting string is <strong>not</strong> a palindrome and that it is the <strong>lexicographically smallest</strong> one possible.</p>
<p>Return <em>the resulting string. If there is no way to replace a character to make it not a palindrome, return an <strong>empty string</strong>.</em></p>
<p>A string <code>a</code> is lexicographically smaller than a string <code>b</code> (of the same length) if in the first position where <code>a</code> and <code>b</code> differ, <code>a</code> has a character strictly smaller than the corresponding character in <code>b</code>. For example, <code>"abcc"</code> is lexicographically smaller than <code>"abcd"</code> because the first position they differ is at the fourth character, and <code>'c'</code> is smaller than <code>'d'</code>.</p>
<strong>Explanation:</strong> There are many ways to make "abccba" not a palindrome, such as "<u>z</u>bccba", "a<u>a</u>ccba", and "ab<u>a</u>cba".
Of all the ways, "aaccba" is the lexicographically smallest.
