GJXW
      +---------
VVGQW | NLTWHLJV
       -WWHPH
        =====
        GHMMYL
       -QRLNUN
        ======
         HZWMGJ
        -HVGTVG
         ======
          PMTXHV
         -PVPVYH
          ======
           GZZHQ

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard