import Data.Char (ord)
import Crypto.Hash.SHA256 (hash)
import Data.ByteString (unpack, pack)
import Text.Printf (printf)

main = putStrLn $                     
       concatMap (printf "%02x") $    
       unpack $                       
       hash $                         
       pack $                         
       map (fromIntegral.ord)         
       "Rosetta code"