XGM
      +--------
LWMFU | QJFPPWW
       -QNGHR
        =====
         YTRHW
        -YYMNY
         =====
          XGXTW
         -XQHPL
          =====
           LTLR

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: challenging
hints: G << R, Q << W, X << F