Maxima: Identifying powers of x1, x2, ..., xn in sum of expressions.

Hi all,

Any assistance with the following would be appreciated:

I have a sum of expressions: s = t1 + t2 + .... + tm.

If any term ti contains one or more of n symbolic variables, each raised to 
the power 2 or higher, that is, x1^p, x2^p, ...., xn^p, p>=2, then that term 
ti should be removed from the sum.

Its not clear how to implement the above in Maxima. I am currently using 
Maxima version 5.12.

Thanks very much.

Regards,

C. Frangos.