XHG
      +--------
EGWXL | WRUEENU
       -EGWXL
        =====
        QQENQN
       -QFWLTU
        ======
         UTLHLU
        -UGLNHX
         ======
          LFLGL

base: 13
letters: EFGHJLNQRTUWX
difficulty: medium
missing: J