Special Pairs.

You are given an array A of N elements. You have to find number of Special Pairs such that i < j (0\(\leq\) i , j \(\leq\)N-1) and A[i] > 2*A[j].

Input Format

• First line contains a single integer N - number of elements in the array
• Second line contains N integers A₀, A₁, … , A_N-1 - elements of an array A.

Output Format

A single integer denoting the number of Special Pairs.

Constraints

• 1 \(\leq\) N \(\leq\) 10⁶
• 1 \(\leq\) A_i \(\leq\) 10⁹

Sample Input 0

5 
1 3 2 3 1

Sample Output 0

2

Sample Input 1

5
2 4 3 5 1

Sample Output 1

3