RNXJ
      +---------
FNJGL | YHPTGWPT
       -MYJTR
        =====
        RXQUQW
       -RRGYNN
        ======
         LWRHNP
        -LNWYJX
         ======
          FXXTXT
         -FLTGXJ
          ======
           RGMJP

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard