????????
      ----------
CHNPY ) YNNYTUCX
       -CHNPY
        =====
        QNHUCU
       - CHNPY
        ======
         PXXFWC
        -PCUWQP
         ======
          FTCNUX
         -FUQQRP
          ======
          ??????

base: 12
symbols: CFHNPQRTUWXY
difficulty: medium