???????
      +--------
XUETG | YLYWEGE
       -XUETG
        =====
        JLHHJG
       -LYUJWY
        ======
         XEQWUE
        -XPEPJX
         ======
         ??????

base: 13
letters: EFGHJLPQTUWXY
difficulty: challenging
attributes: intricate
missing: F