class Solution:
    def longestPalindrome(self, s: str) -> str:

        res = ""
        n = len(s)
        dp = [[False]*n]*n

        for j in range(n):
            for i in range(j+1):
                if i==j:
                    dp[j][i] = True
                elif j==i+1:
                    dp[j][i] = (s[i] == s[j])
                else:
                    dp[j][i] = (dp[j-1][i+1] and s[i]==s[j])

                if len(res) < j-i+1 and dp[j][i]:
                    res = s[i:j+1]

        return res