JLTL
      +---------
WJHPG | GGHMPRUM
       -JRMZU
        =====
         NPMJR
        -YYQJR
         =====
          VXZZU
         -QUGTV
          =====
           NLUVM
          -YYQJR
           =====
            NLTV

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: medium