FPFJ
      +---------
FFWLT | FLJRJJJN
       -FFWLT
        =====
         UFHNJ
        -PRGNL
         =====
          YFMYJ
         -FFWLT
          =====
           RGNNN
          -QXTHM
           =====
            JYGN

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard