PQP
      +---------
EYYMY | EJQNRPJP
       -WLGYQR
        ======
         YMPNNJ
        -YYGNEL
         ======
          WLPTYP
         -WLGYQR
          ======
            PEQN

base: 13
letters: EGJLMNPQRTUWY
difficulty: medium
restrictions: no multiplication
missing: U