????????
      +---------
WHQEW | JLYYFQYJ
       -WHQEW
        =====
        WWEPYQ
       -WUMJHM
        ======
          MLQWY
         -MWQFH
          =====
           HRMQJ
          -HWJGF
           =====
           ?????

base: 13
letters: EFGHJLMPQRUWY
difficulty: hard