input: Write a python function to find palindromes in a given string.
  assert find_palindromes("madamabcdcba") == ['madam', 'aba', 'bcdcb', 'cdc', 'abcdcba']
  assert find_palindromes("racecar") == ['racecar', 'aceca', 'cec']
  assert find_palindromes("banana") == ['anana', 'ana', 'nan']
output: def find_palindromes(s):
      def is_palindrome(sub):
          return sub == sub[::-1]
  
      n = len(s)
      palindromes = []
      for i in range(n):
          for j in range(i + 2, n + 1):
              substring = s[i:j]
              if is_palindrome(substring):
                  palindromes.append(substring)
      return palindromes