new_contents: """ Project Euler problem #4. """
  
  import itertools as it
  
  
  def problem():
      u""" Solve the problem.
  
      A palindromic number reads the same both ways. The largest palindrome made
      from the product of two 2-digit numbers is 9009 = 91 * 99.
  
      Find the largest palindrome made from the product of two 3-digit numbers.
  
      Answer: 906609
  
      """
      return max([
          x for x in [
              a * b for a, b in it.product(range(999, 900, -1), repeat=2)]
          if is_palindrome(x)
      ])
  
  
  def is_palindrome(num):
      """ Check for number is palindrome. """
      num = str(num)
      return num == num[::-1]
  
  
  if __name__ == '__main__':
      print problem()
  
subject: Solve 4.