????????
      +---------
GFFQG | PGJJPERW
       -FHGGY
        =====
        GGPPTE
       -GHFLME
        ======
         GHEYHR
        -GHFLME
         ======
           PRHWW
          -PFPEF
           =====
           ?????

base: 13
letters: EFGHJLMPQRTWY
difficulty: medium