YEMQ
      +---------
QPRPX | QXUWELFM
       -QPRPX
        =====
         YLYPLF
        -YEXLPW
         ======
          YXMRQM
         -YTEFEL
          ======
           LLHQY

base: 13
letters: EFHLMPQRTUWXY
difficulty: intermediate
restrictions: no multiplication