????????
      +---------
YEUGF | HNGNJEWR
       -YEUGF
        =====
        WRWYEE
       -WXJPER
        ======
         YXERFW
        -UHPWGU
         ======
          FXHGUR
         -EHJNUP
          ======
          ??????

base: 13
letters: EFGHJNPQRUWXY
missing: Q
difficulty: medium
hints: P << U