????????
      +---------
YXQFG | YNHQQQLH
       -YXQFG
        =====
         RYLFQ
        -QGMUH
         =====
          TGMML
         -TTXWX
          =====
           XQMJH
          -UYFXW
           =====
           ?????

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard
missing: P