?????????
      +----------
NWTWM | TMLNWVRMT
       -VMVMG
        =====
        PQXZNV
       -RTYNYY
        ======
         PTRHNR
        -PLXLXT
         ======
          XXNRJM
         - WTJTZ
          ======
           RZLGJT
          -RZJZJU
           ======
           ??????

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard