???????
      +--------
FHNTW | EMXXTMT
       -UEUJM
        =====
         MGNWM
        -FHNTW
         =====
         FQEGUT
        -FQHFUT
         ======
         ??????

base: 13
letters: EFGHJMNPQTUWX
difficulty: hard
missing: P