????????
      +---------
MGNEW | TLXLLGQT
       -XUPMT
        =====
        NWNPRG
       -NQRLGX
        ======
         MNTXRQ
        -METRTN
         ======
           RQMGT
          -UNXGQ
           =====
           ?????

base: 13
letters: EGLMNPQRTUWXY
difficulty: medium
missing: Y