????????
      +---------
JQEQE | PEPPREYU
       -UPWPR
        =====
        FWHXXE
       -FWEYET
        ======
          TXRHY
         -UPWPR
          =====
           UYEEU
          -UPWPR
           =====
           ?????

base: 13
letters: EFHJMPQRTUWXY
difficulty: hard
missing: M