class Solution:
    def longestPalindrome(self, s: str) -> str:
        longestSubstring = ""
        substring = ""
        stringLength = len(s)
        if self.isPalindrome(s, stringLength):
            return s
        endIndex = stringLength + 1
        for i in reversed(range(endIndex)):
            for j in range(i):
                substringLength = i - j
                if len(longestSubstring) < substringLength:
                    substring = s[j:i]
                    if self.isPalindrome(substring, substringLength):
                        longestSubstring = substring

        return longestSubstring

    def isPalindrome(self, s: str, stringLength: int) -> bool:
        """Takes a string and returns True if the string is a palindrome
        Arguments:
            s {str} -- The string to be tested
            stringLength {int} -- The length of the string
        Returns:
            bool -- True if it's a palindrome, False if it's not
        """

        if stringLength < 2:
            return True

        midpoint = stringLength // 2
        if stringLength % 2 != 0:
            # It's odd, so the midpoint doesn't matter
            if s[:midpoint] == s[:midpoint:-1]:
                return True
            return False
        else:
            # It's even
            if s[:midpoint] == s[: midpoint - 1 : -1]:
                return True
            return False