;Task: Implement a [[wp: Playfair cipher| Playfair cipher]] for encryption and decryption. The user must be able to choose   '''J'''  =  '''I'''     or   no   '''Q'''   in the alphabet. The output of the encrypted and decrypted message must be in capitalized digraphs, separated by spaces. ;Output example: HI DE TH EG OL DI NT HE TR EX ES TU MP