Score : 300 points
You are given N real values A_1, A_2, \ldots, A_N. Compute the number of pairs of indices (i, j) such that i < j and the product A_i \cdot A_j is integer.
Input is given from Standard Input in the following format.
N A_1 A_2 \vdots A_N
Print the number of pairs with integer product A_i \cdot A_j (and i < j).
5 7.5 2.4 17.000000001 17 16.000000000
3
There are 3 pairs with integer product:
11 0.9 1 1 1.25 2.30000 5 70 0.000000001 9999.999999999 0.999999999 1.000000001
8