class Solution:
  def findLPSLength(self, st):
    
    def is_palindrom(s):
      i = 0
      j = len(s) - 1
      while i <= j:
        if s[i] != s[j]:
          return False
        i += 1
        j -= 1
      return True
    
    def dp(index, s, memo):
      if s in memo:
        return memo[s]

      if is_palindrom(s):       
        return len(s)

      if index >= len(s):
        return 0

      skip_char = dp(index + 1, s[:], memo)

      with_char = dp(index + 1, s[:index] + s[index+1:], memo)

      result = max(skip_char, with_char)

      memo[s] = result
      
      return result

    return dp(0, st, {})