XXUX
       +-----------
QQYFCC | YQCCTUCUGX
        -YYFXTTX
         =======
          YQFGQJU
         -YYFXTTX
          =======
           YEYCYGG
          -JQXJCET
           =======
            YTUQGFX
           -YYFXTTX
            =======
             XYFEYE

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