QUL
      +--------
VQTXM | PQQJVZM
       -VQTXM
        =====
        QTQTQZ
       -QWNNUH
        ======
         RVQXPM
        -RYTNQL
         ======
          MQNVZ

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