????????
      +---------
MUQLL | URNNNPTN
       -MUQLL
        =====
        QFTJJP
       -QYLFXX
        ======
         FRXFXT
        -FMNNRW
         ======
          FWMNFN
         -FMNNRW
          ======
          ??????

base: 13
letters: FJLMNPQRTUWXY
difficulty: hard
attributes: fun