????????
      +---------
FWMNU | LFCQQYLL
       -FWMNU
        =====
        QHNNUY
       -YNXXHR
        ======
         QMXHYL
        -QQQFMU
         ======
          WWWCML
         -QLXWWQ
          ======
          ??????

base: 12
letters: CFHLMNQRUWXY
difficulty: medium