Is it Obvious

You are given two integers $N$ and $M$. Let $\text{pr}(x)$ denote the number of distinct **prime** factors of $x$. Count the number of integer arrays $A$ such that: - $A$ has length $N$. - $1 \leq A_i \leq M$, and all the elements of $A$ are **distinct**. - $\text{pr}(A_i) \leq \text{pr}(A_j)$ for $1 \leq i \lt j \leq N$. The number of such arrays can be large, so print the answer modulo $99