MPCT
    +--------
TNM | MMACYAG
     -HGTY
      ====
       PAPY
      -MGNA
       ====
        CGYA
       - TNM
        ====
         GGYG
        -GNYY
         ====
          CAR

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