????????
      +---------
JVYWL | QWQGQNZN
       -JVYWL
        =====
        JZNZTN
       -JWUTLZ
        ======
         XRPMTZ
        -XMQRLG
         ======
          JMPTHN
         -JQLJWW
          ======
          ??????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard