println(scala.io.StdIn.readLine().foldLeft("")((acc:String , x) => if (acc.contains(x)) acc else acc + x))

import qualified Data.Set as S

remDupe "" _ = ""
remDupe (c:cs) seen = 
  if S.member c seen
  then remDupe cs seen
  else c:(remDupe cs $ S.insert c seen)

main = do cs <- getLine
          putStr $ remDupe cs S.empty

import           Data.List (nub)

main :: IO ()
main = interact nub

(defn remove-duplicates [input-string seen]
        (if (not (empty? input-string))
            (let [current-char (first input-string)]
                (if (.contains seen (str current-char)) 
                    (remove-duplicates (rest input-string) seen)
                    (remove-duplicates (rest input-string) (str seen current-char))))
            seen))

(println (remove-duplicates (read-line) ""))

(println (apply str (distinct (read-line)))