GGG
      +---------
HXLXX | HXLEUFFQ
       -HPPJGP
        ======
         HJXUGF
        -HPPJGP
         ======
          HHHGGQ
         -HPPJGP
          ======
           UUPLF

base: 13
letters: EFGHJLMPQUWXY
difficulty: hard
restrictions: one multiplication
hints: Y < U, E = Q * Q, W << M
missing: M W Y