(function in-block? c
  (when (let block-idx (find-idx (substr? (upper-case c)) rem-blocks))
    (var! rem-blocks drop block-idx)))

(function can-make-word word
  (var rem-blocks ["BO" "XK" "DQ" "CP" "NA" "GT" "RE" "TG" "QD" "FS" "JW" "HU" "VI" "AN" "OB" "ER" "FS" "LY" "PC" "ZM"])
  (.. and (map in-block? word)))

(-> ["A" "bark" "Book" "TREAT" "Common" "squaD" "CoNFuSe"] ; Notice case insensitivity
    (map #"{%} => {can-make-word %}")
    (join ", "))