JVHR
      +---------
VNWQV | QGUXUJXP
       -RWPGL
        =====
        JPMPYJ
       -JMRRLW
        ======
         UPZXGX
        -UHGGGJ
         ======
          YLNTVP
         -YVVTMG
          ======
           VHQGZ

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard