UYX
      +--------
XUQUQ | MGMXMWU
       -XUQUQ
        =====
        UMMYMW
       -UYYQYQ
        ======
         WWYWWU
        -UNXQXQ
         ======
          YLUNU

base: 9
letters: GLMNQUWXY
difficulty: medium
restrictions: no multiplication