import Control.Monad

ver simbol l acc text =
  case l of  
   l1:ls -> if simbol == l1 then ver simbol ls (acc+1) text else ver simbol ls acc text
   []-> acc / (fromIntegral $ length text)

prob simbol text = ver simbol text 0 text

loge2 = log 2
log2 a=  log a/ loge2

inf n text = if (prob n text) == 0 then 0 else (-1)*(prob n text)*(log2 (prob n text))

iinf l text=
  case l of        
   l1:ls-> (inf l1 text)+(iinf ls text)
   []->0

main = do
  print $ iinf ("mama myla ramu") ("mama myla ramu")