Enter the postfix expression that the following tree represents.

You don't need to put spaces between characters but you can, if it helps.

All characters in this question are lower case.

Answer: $($penalty regime: $10,20,$dots$\%)$

Sorry, that's incorrect!

Your simplified answer $=x{r}^{**}{w}^{**}y+m\frac{s}{-}$cdots

Marks for this submission: $\frac{0\mathrm{.}00}{2\mathrm{.}00}.$ This submission attracted a penalty of $0\mathrm{.}40.$