????????
      +---------
UNFEE | XWFYXQEN
       -XEYLL
        =====
         GGHTQ
        -UNFEE
         =====
          TLWUE
         -NHYGU
          =====
          UJTFGN
         -UJUNJF
          ======
          ??????

base: 14
letters: EFGHJLMNQTUWXY
difficulty: medium
missing: M