XHY
      +--------
XGAQY | JGHJUJJ
       -QXHWH
        =====
        GYWUHJ
       -GJWJHX
        ======
         GYYWQJ
        -GYXGAG
         ======
           UYGU

base: 9
letters: AGHJQUWXY
difficulty: intermediate
restrictions: no multiplication