CUCM
      +---------
WUCGF | GUMCYGQF
       -CFUYQ
        =====
         QNMWG
        -MQLMC
         =====
          GMQWQ
         -CFUYQ
          =====
           YWUNF
          -YWWLN
           =====
             CWF

base: 10
letters: CFGLMNQUWY
difficulty: easy
restrictions: no multiplication