RUMM
      +---------
VQZVT | MTXJZQHU
       -QHWZR
        =====
        TGGXUQ
       -TMQTZU
        ======
         HYLGHH
        -HRZNPM
         ======
          HYHUZU
         -HRZNPM
          ======
           RNMMM

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard
hints: Q != 0