????????
      +---------
FYYLM | MJJGYTFR
       -MUGLY
        =====
         JRPUT
        -TQJLR
         =====
         PXHULF
        -PMJPMT
         ======
           QXGMR
          -TQJLR
           =====
           ?????

base: 13
letters: FGHJLMPQRTUXY
difficulty: medium