A11806 | GCD Counting

You are given a tree consisting of $n$ vertices. A number is written on each vertex; the number on vertex $i$ is equal to $a_i$ .

Let's denote the function $g(x, y)$ as the greatest common divisor of the numbers written on the vertices belonging to the simple path from vertex $x$ to vertex $y$ (including these two vertices).

For every integer from $1$ to $2 \cdot 10^5$ you have to count the number of pairs $(x, y)$ $(1 \le x \le y \le n)$ such that $g(x, y)$ is equal to this number.

The first line contains one integer $n$ — the number of vertices $(1 \le n \le 2 \cdot 10^5)$ .

The second line contains $n$ integers $a_1$ , $a_2$ , ..., $a_n$ $(1 \le a_i \le 2 \cdot 10^5)$ — the numbers written on vertices.

Then $n - 1$ lines follow, each containing two integers $x$ and $y$ $(1 \le x, y \le n, x \ne y)$ denoting an edge connecting vertex $x$ with vertex $y$ . It is guaranteed that these edges form a tree.

For every integer $i$ from $1$ to $2 \cdot 10^5$ do the following: if there is no pair $(x, y)$ such that $x \le y$ and $g(x, y) = i$ , don't output anything. Otherwise output two integers: $i$ and the number of aforementioned pairs. You have to consider the values of $i$ in ascending order.

See the examples for better understanding.