GYF
       +---------
LFLYAM | PGMLFGEC
        -LFLYAM
         ======
         APFPAAE
        -AEYPGTL
         =======
          GCTGAGC
         -GYPCPEF
          =======
            LAFYL

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