Filtering an expression: keeping only term with even power
In the expression $$ x^2 y^2+x y^2+x^3y + 5 x^4 y^4 $$ I would like to keep only the term where the variables have even power $$ x^2y^2+5 x^4 y^4 $$
Is there a way to do it?
I look into this post.
But once I get the operands, I don't see how to analyze the variable exponent.