Cool Checker

*Pritesh was assigned to write the checker for problem Cool Subsequences. He found this to be an interesting problem on its own.* You are given two arrays $A$ and $B$ of lengths $N$ and $M$, respectively. A non-empty [subsequence](https://en.wikipedia.org/wiki/Subsequence) $S$ of the array $A$ is said to be *legal* if $\mathrm{AVG}(S) \in B$, where $\mathrm{AVG}(S)$ is the average of the elemen