????????
      +---------
WQULY | LZYXRNYL
       -WQULY
        =====
        QNVLYN
       -NGLPYJ
        ======
         ZNTMYY
        -RLUZTT
         ======
          QXYRRL
         -QJNHUN
          ======
          ??????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard