????????
      +---------
PQRUW | MPUUYMJM
       -LUJGW
        =====
        QNPYYM
       -QMQPPW
        ======
         QJUUMJ
        -JXRRJW
         ======
          JGNYJM
         -JMEXMW
          ======
          ??????

base: 13
letters: EGJLMNPQRUWXY
difficulty: medium