????????
      +---------
PGTGY | YTREWYGF
       -PGTGY
        =====
        REYWRY
       -RGWGRX
        ======
         RXGWRG
        -RGWGRX
         ======
          CFFYPF
         -CWRWCE
          ======
          ??????

base: 10
letters: CEFGPRTWXY
difficulty: easy