XGJT
        +-----------
QGJYCWX | TWUYJCQYGT
         -QGJYCWX
          =======
          YCYWXCGY
         -YXTUWGWG
          ========
           GHXXYHTG
          -HTHWTYWJ
           ========
            GTWGXJJT
           -GHJTWTWT
            ========
             GYCWUJW

base: 10
letters: CGHJQTUWXY
difficulty: intermediate
restrictions: no multiplication