题目描述
Problem Statement
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
Input is given from Standard Input in the following format.
N
A_1
A_2
$\vdots$
A_N
Output
Print the number of pairs with integer product $A_i \cdot A_j ($and i < j).
Constraints
- $2 \leq N \leq 200$\,000
- 0 < A_i < 10^4
- A_i is given with at most 9 digits after the decimal.
Sample Input 1
5
7.5
2.4
17.000000001
17
16.000000000
Sample Output 1
3
There are 3 pairs with integer product:
- 7.$5 \cdot 2.4 = 18$
- 7.$5 \cdot 16 = 120$
- $17 \cdot 16 = 272$
Sample Input 2
11
0.9
1
1
1.25
2.30000
5
70
0.000000001
9999.999999999
0.999999999
1.000000001
Sample Output 2
8
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
5
7.5
2.4
17.000000001
17
16.000000000
样例输出
3