NQQQ
     +---------
XHQF | QXGLYMYG
      -QYNYM
       =====
        QLQXM
       -HMQAQ
        =====
         QLGFY
        -HMQAQ
         =====
          QQHAG
         -HMQAQ
          =====
           NXLQ

base: 10
letters: AFGHLMNQXY
difficulty: medium
restrictions: no multiplication