???????
      +--------
FXTHH | EGNPYFJ
       -FXTHH
        =====
        NRUPGF
       -NERXHQ
        ======
         NHNGJJ
        -NTYYHU
         ======
         ??????

base: 14
letters: EFGHJLNPQRTUXY
difficulty: hard
missing: L