????????
      +---------
QNHHF | UQYPMEQH
       -NHPPT
        =====
         HNUPE
        -LTQQL
         =====
         QMTQYQ
        -QRRYPY
         ======
          MFNNUH
         -MHYMMN
          ======
          ??????

base: 13
letters: EFGHLMNPQRTUY
difficulty: medium
missing: G