CYCH
      +---------
MQEYM | NHMWHHGC
       -MQEYM
        =====
        QJPNYH
       -QNMMCW
        ======
          GEGGG
         -MQEYM
          =====
          CCCNCC
         - JGNMJ
          ======
           CMJGH

base: 11
letters: CEGHJMNPQWY
difficulty: medium
restrictions: no multiplication