#P840C. On the Bench
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ID: 3966
Type: RemoteJudge
2000ms
256MiB
Tried: 0
Accepted: 0
Difficulty: (None)
Uploaded By:
Hydro
Tags> On the Bench
No submission language available for this problem.
Description
A year ago on the bench in public park Leha found an array of n numbers. Leha believes that permutation p is right if for all 1 ≤ i < n condition, that api·api + 1 is not perfect square, holds. Leha wants to find number of right permutations modulo 109 + 7.
First line of input data contains single integer n (1 ≤ n ≤ 300) — length of the array.
Next line contains n integers a1, a2, ... , an (1 ≤ ai ≤ 109) — found array.
Output single integer — number of right permutations modulo 109 + 7.
Input
First line of input data contains single integer n (1 ≤ n ≤ 300) — length of the array.
Next line contains n integers a1, a2, ... , an (1 ≤ ai ≤ 109) — found array.
Output
Output single integer — number of right permutations modulo 109 + 7.
Samples
3
1 2 4
2
7
5 2 4 2 4 1 1
144
Note
For first example:
[1, 2, 4] — right permutation, because 2 and 8 are not perfect squares.
[1, 4, 2] — wrong permutation, because 4 is square of 2.
[2, 1, 4] — wrong permutation, because 4 is square of 2.
[2, 4, 1] — wrong permutation, because 4 is square of 2.
[4, 1, 2] — wrong permutation, because 4 is square of 2.
[4, 2, 1] — right permutation, because 8 and 2 are not perfect squares.