QMTZ
      +---------
VTRHZ | JUZGMJGL
       -JXYJG
        =====
         UGGUJ
        -HGMJT
         =====
         VXYWVG
        -MNRRZG
         ======
          VQLYXL
         -VQLQZQ
          ======
              MY

base: 16
letters: GHJLMNPQRTUVWXYZ
difficulty: hard
missing: P