GUMG
      +---------
QNQYQ | NRNZTYGH
       -QNQYQ
        =====
        JTJNXY
       -JLNRWH
        ======
         GXVUMG
        -GQZHNZ
         ======
           RMHNH
          -QNQYQ
           =====
           MHTPT

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