URQP
      +---------
LMLQL | PHWXPLTR
       -LMLQL
        =====
        GGTLGL
       -MJFMHR
        ======
         LTYRPT
        -XPTXLN
         ======
          GQMMRR
         -GPHGNH
          ======
           UHQYU

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: medium
missing: U