RVPL
      +---------
RQNMW | HLGYNZMW
       -HHLJU
        =====
         WHLNZ
        -WULVW
         =====
          HUTPM
         -RQNMW
          =====
          RHTQLW
         -RHZXYU
          ======
            VVVW

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: medium