题目描述
Problem Statement
You are given $N integers A_1,\ldots,A_N$ and a prime number P. Find the number of pairs of integers (i,j) that satisfy both of the following conditions:
- $1 \leq i,j \leq N$;
- There is a positive integer k such that $A_i^k \equiv A_j \mod P$.
Input
The input is given from Standard Input in the following format:
N P
$A_1 \ldots A_N$
Output
Print the answer.
Constraints
- $2 \leq N \leq 2 \times 10^5$
- $1 \leq A_i < P$
- $2 \leq P \leq 10^{13}$
- P is prime.
- All input values are integers.
Sample Input 1
3 13
2 3 5
Sample Output 1
5
Five pairs satisfy the conditions: (1,1),(1,2),(1,3),(2,2),(3,3).
For example, for the pair (1,3), if we take k=9, then $A_1^9 = 512 \equiv 5 = A_3 \mod 13$.
Sample Input 2
5 2
1 1 1 1 1
Sample Output 2
25
Sample Input 3
10 9999999999971
141592653589 793238462643 383279502884 197169399375 105820974944 592307816406 286208998628 34825342117 67982148086 513282306647
Sample Output 3
63
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分