# A riddle, guess the word from the sum

What is \displaystyle \left(a\sum_{n=2}^\infty w^n\right)!

If you can't figure it out, here are 2 hints.

Hint 1: What is \sum_{V\subseteq U} \dim(V)? Where U is a vector space of dishes for a yum cha.

Hint 2: On the internet, you will see the following variation. \displaystyle \left(a\sum_{n=2}^\infty w^n\right)!!!!