????????
      +---------
QRJRU | LFXRJPJC
       -CUFCJ
        =====
        PRLPTP
       -PFQPXX
        ======
         QFLFCJ
        -QXXFCX
         ======
          PXLLRC
         -PPXRFR
          ======
          ??????

base: 10
letters: CFJLPQRTUX
difficulty: medium
attributes: good demo