????????
      +---------
XTHXE | QNQTNJQN
       -XTHXE
        =====
        MRNHMJ
       -MYMGWH
        ======
         RMRERQ
        -RYREWT
         ======
          JWWJJN
         -JXQQEN
          ======
          ??????

base: 13
letters: EFGHJMNQRTWXY
difficulty: medium
missing: F