class Solution:
    def longestPalindrome(self, s: str) -> str:
        
Given a string s, return the longest 
palindromic
substring
 in s.

 

Example 1:

Input: s = "babad"
Output: "bab"
Explanation: "aba" is also a valid answer.
Example 2:

Input: s = "cbbd"
Output: "bb"
 

Constraints:

1 <= s.length <= 1000
s consist of only digits and English letters.