Crypto Square problem

gistfile1.clj

(defn crypto-square [s]
  (->> (re-seq #"\w+" s)
       (map clojure.string/lower-case)
       (apply str)
       (#(let [size (int (Math/ceil (Math/sqrt (count %))))]
           (partition size size (repeat " ") %)))
       (apply map vector)
       (map (partial apply str)) 
       (clojure.string/join "\n")))

(println (crypto-square "If man was meant to stay on the ground god would have given us roots"))
;; imtgdvs
;; fearwer
;; mayoogo
;; anouuio
;; ntnnlvt
;; wttddes
;; aohghn 
;; sseoau