YAWRW
     +---------
YFRU | FAWXPWRY
      -RRXY
       ====
       YLYPP
      -YYMWA
       =====
        XYRXW
       -XXMYW
        =====
         XWPMR
        -XLFAM
         =====
          XXYRY
         -XXMYW
          =====
            YYA

base: 10
letters: AFLMPRUWXY
difficulty: medium
restrictions: no multiplication