????????
      ----------
ETPFX ) TPMFXMQP
       -TUXRX
        =====
         PUCUM
        -ETPFX
         =====
          WPQEQ
         -WEEQU
          =====
           EMTQP
          -ETPFX
           =====
           ?????

base: 12
symbols: CEFMPQRTUWXY
difficulty: medium
missing: Y