Problem I. Inverse of sum
时间限制 3000 ms
内存限制 512 MB
There are $n$ nonnegative integers $a_{1…n}$ which are less than $p$. HazelFan wants to know how many pairs $i,j(1\leq i<j\leq n)$ are there, satisfying $\frac{1}{a_i+a_j}\equiv\frac{1}{a_i}+\frac{1}{a_j}$ when we calculate module $p$, which means the inverse element of their sum equals the sum of their inverse elements. Notice that zero element has no inverse element.
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输出数据
For each test case:
A single line contains a nonnegative integer, denoting the answer.
样例输入
复制
2
5 7
1 2 3 4 5
6 7
1 2 3 4 5 6
样例输出
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