????????
      +---------
XMQTR | HMXRLXTP
       -XMQTR
        =====
        JWQLJX
       -QNPRHW
        ======
         PPQLXT
        - NHXFH
         ======
          PFPNPP
         -PXFHRW
          ======
          ??????

base: 12
letters: FHJLMNPQRTWX
difficulty: medium