????????
      +---------
XYEUY | GJHUELTR
       -XYEUY
        =====
        XUMGTL
       -QYLUJX
        ======
         XRNNXT
        -QYLUJX
         ======
          UYQQUR
         -UQQTJJ
          ======
          ??????

base: 14
letters: EGHJLMNPQRTUXY
difficulty: medium
missing: P