UJL
      +--------
RRMWR | UQNWXGW
       -UHJQU
        =====
         FQPFG
        -JQYQJ
         =====
         RTYMJW
        - GJLHL
         ======
           MLHF

base: 15
letters: FGHJLMNPQRTUWXY
difficulty: hard