FJE
     +-------
QPGG | EEPCXW
      -WCUQ
       ====
       FGXEX
      -FCRQN
       =====
        QCPXW
       -QCNEQ
        =====
          JFU

base: 12
letters: CEFGJNPQRUWX
difficulty: medium
missing: J