???????
      +--------
UHQQJ | PRLYRQE
       -UHQQJ
        =====
         FRQMQ
        -UHQQJ
         =====
         MEJELE
        -MWHPFE
         ======
         ??????

base: 13
letters: EFHJLMPQRUWXY
difficulty: medium
attributes: indirect
hints: L << Y, R << W
missing: X