import Data.Char

main = guess 1 10

query ot = do putStr ot
              ans <- getLine
              pure (ans == "ano")

guess :: Int -> Int -> IO ()
guess m n = do putStrLn ("Mysli si cele cislo od " ++ show m
                         ++ " do " ++ show n ++ ".")
               kv m n

kv m n = do
     if m == n
     then putStrLn ("Je to " ++ show m ++ ".")
     else do o <- query $ "Je tve cislo vetsi nez " ++ show k ++ "? "
             if o then kv (k + 1) n else kv m k
  where k = (m + n) `div` 2