????????
      +---------
ZYLWX | YUHMLLMH
       -JRTUM
        =====
        XRJMGL
       -XMLJZL
        ======
         PMJJNM
        -PZXWVQ
         ======
          ZVWMTH
         -ZWVTRT
          ======
          ??????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: intermediate