????????
      +---------
EXXJE | ERTTEQWQ
       -EXXJE
        =====
         RTLXQ
        -RXQWR
         =====
          MMRRW
         -MXQMM
          =====
           MWMQQ
          -MXQMM
           =====
           ?????

base: 10
letters: EJLMQRTWXY
difficulty: hard
missing: Y