class Solution:
    def getLongestPalindrome(self, A: str) -> int:
        n = len(A)
        if n < 2:
            return n

        max_length = 1

        def expandAroundCenter(left: int, right: int) -> int:
            while left >= 0 and right < n and A[left] == A[right]:
                left -= 1
                right += 1
            return right - left - 1

        for i in range(n):
            len1 = expandAroundCenter(i, i)  # 单字符作为中心
            len2 = expandAroundCenter(i, i + 1)  # 两个字符之间的空隙作为中心(针对偶数长度的回文子串)
            max_length = max(max_length, len1, len2)

        return max_length