THV
      +--------
VLNPW | GVMUNTR
       -VLNPW
        =====
        PPZNZT
       -PQJXYW
        ======
         LZMQJR
        -LWNHUM
         ======
          PYVWJ

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: medium