new_contents: def ascii_cipher(message, key):
      pfactor = max(
                  i for i in range(2, abs(key)+1)
                      if is_prime(i) and key%i==0
                   )*(-1 if key<0 else 1)
      return ''.join(chr((ord(c)+pfactor)%128) for c in message) 
      
      
  def is_prime(n):
      if n < 2: return False
      return all( n%i!=0 for i in range(2, round(pow(n,0.5))+1) ) or n==2
  
subject: Create 6kyu_ascii_cipher.py