Problem:
Score : 300 points

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.

Constraints

2 \leq N \leq 200\,000

0 < A_i < 10^4

A_i is given with at most 9 digits after the decimal.

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).

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

Solution in Ruby (2.7.1) (judge verdict: Time Limit Exceeded)

N = gets.to_i
A = []
N.times{
  tmp = gets.chomp
  if tmp.split(".").size == 1
    A.push(tmp.to_i * 10**9)
  else
    A.push((Rational(tmp) * 10**9).to_i)
  end
}

count = 0

0.upto(N-2){ |i|
  (i+1).upto(N-1){ |j|
    #puts A[i], A[j]
    tmp = A[i] * A[j]
    #p tmp
    if (tmp % 10**18) == 0
      #puts 'yes'
      count += 1
    end
    #puts
  }
}

puts count