module Main where

import Data.List (transpose)

solve :: String -> String
solve plain = encrypted
  where
    plain' = filter (/= ' ') plain
    len = length plain'
    rows = floor . sqrt $ fromIntegral len
    cols = ceiling . sqrt $ fromIntegral len
    grid = [take cols $ drop (i * cols) plain' | i <- [0 .. rows]]
    grid' = filter (/= "") grid -- edge case, final is ""
    encrypted = unwords $ transpose grid

main :: IO ()
main = interact solve