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A11887. Appropriate Team

编程题 普及/提高-

题目描述

Since next season are coming, you'd like to form a team from two or three participants. There are $n$ candidates, the $i$ -th candidate has rank $a_i$ . But you have weird requirements for your teammates: if you have rank $v$ and have chosen the $i$ -th and $j$ -th candidate, then $GCD(v, a_i) = X$ and $LCM(v, a_j) = Y$ must be met.

You are very experienced, so you can change your rank to any non-negative integer but $X$ and $Y$ are tied with your birthdate, so they are fixed.

Now you want to know, how many are there pairs $(i, j)$ such that there exists an integer $v$ meeting the following constraints: $GCD(v, a_i) = X$ and $LCM(v, a_j) = Y$ . It's possible that $i = j$ and you form a team of two.

$GCD$ is the greatest common divisor of two number, $LCM$ — the least common multiple.

输入格式

First line contains three integers $n$ , $X$ and $Y$ ( $1 \le n \le 2 \cdot 10^5$ , $1 \le X \le Y \le 10^{18}$ ) — the number of candidates and corresponding constants.

Second line contains $n$ space separated integers $a_1, a_2, \dots, a_n$ ( $1 \le a_i \le 10^{18}$ ) — ranks of candidates.

输出格式

Print the only integer — the number of pairs $(i, j)$ such that there exists an integer $v$ meeting the following constraints: $GCD(v, a_i) = X$ and $LCM(v, a_j) = Y$ . It's possible that $i = j$ .

输入输出样例

输入 #1
12 2 2
1 2 3 4 5 6 7 8 9 10 11 12
输出 #1
12
输入 #2
12 1 6
1 3 5 7 9 11 12 10 8 6 4 2
输出 #2
30

说明/提示

In the first example next pairs are valid: $a_j = 1$ and $a_i = [2, 4, 6, 8, 10, 12]$ or $a_j = 2$ and $a_i = [2, 4, 6, 8, 10, 12]$ . The $v$ in both cases can be equal to $2$ .

In the second example next pairs are valid:

- $a_j = 1$ and $a_i = [1, 5, 7, 11]$ ;
- $a_j = 2$ and $a_i = [1, 5, 7, 11, 10, 8, 4, 2]$ ;
- $a_j = 3$ and $a_i = [1, 3, 5, 7, 9, 11]$ ;
- $a_j = 6$ and $a_i = [1, 3, 5, 7, 9, 11, 12, 10, 8, 6, 4, 2]$ .
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