????????
      +---------
JETGE | FGGFTMJX
       -FMJQN
        =====
         EFRXM
        -RRENQ
         =====
         JQXNJJ
        -JJUQEX
         ======
          JELGMX
         -JRRTLG
          ======
          ??????

base: 13
letters: EFGHJLMNQRTUX
difficulty: challenging
missing: H