????????
      +---------
TFTFY | MPUGUEPL
       -TFTFY
        =====
        TEYPTE
       -WMLMWF
        ======
         WPYNGP
        -WWJTNP
         ======
          UMPGNL
         -UQMYNF
          ======
          ??????

base: 14
letters: EFGJLMNPQTUWXY
difficulty: hard
hints: X << P
missing: X