WTTGH
     +---------
NWCH | JQNQGHTJ
      -GQCW
       ====
       HCNGG
      - QNCT
       =====
        HCGNH
       - QNCT
        =====
         HTHJT
        -HWECG
         =====
           WGEJ
          -NWCH
           ====
           HWEG

base: 10
letters: CEGHJNPQTW
difficulty: medium
restrictions: no multiplication
missing: P