????????
      +---------
QEXLL | WLEPTXHT
       -QEXLL
        =====
         GLGLX
        -UTTNN
         =====
          TPLTH
         -XXHLH
          =====
          QHQLRT
         -QWQGTG
          ======
          ??????

base: 13
letters: EGHLNPQRTUWXY
difficulty: intermediate
missing: Y