1166_C. A Tale of Two Lands
The legend of the foundation of Vectorland talks of two integers x and y. Centuries ago, the array king placed two markers at points |x| and |y| on the number line and conquered all the land in between (including the endpoints), which he declared to be Arrayland. Many years later, the vector king placed markers at points |x - y| and |x + y| and conquered all the land in between (including the endpoints), which he declared to be Vectorland. He did so in such a way that the land of Arrayland was completely inside (including the endpoints) the land of Vectorland.

Here |z| denotes the absolute value of z.

Now, Jose is stuck on a question of his history exam: "What are the values of x and y?" Jose doesn't know the answer, but he believes he has narrowed the possible answers down to n integers a_1, a_2, ..., a_n. Now, he wants to know the number of unordered pairs formed by two different elements from these n integers such that the legend could be true if x and y were equal to these two values. Note that it is possible that Jose is wrong, and that no pairs could possibly make the legend true.

Input

The first line contains a single integer n (2 ≤ n ≤ 2 ⋅ 10^5) — the number of choices.

The second line contains n pairwise distinct integers a_1, a_2, ..., a_n (-10^9 ≤ a_i ≤ 10^9) — the choices Jose is considering.

Output

Print a single integer number — the number of unordered pairs \\{x, y\} formed by different numbers from Jose's choices that could make the legend true.

Examples

Input


3
2 5 -3


Output


2


Input


2
3 6


Output


1

Note

Consider the first sample. For the pair \{2, 5\}, the situation looks as follows, with the Arrayland markers at |2| = 2 and |5| = 5, while the Vectorland markers are located at |2 - 5| = 3 and |2 + 5| = 7:

<image>

The legend is not true in this case, because the interval [2, 3] is not conquered by Vectorland. For the pair \{5, -3\} the situation looks as follows, with Arrayland consisting of the interval [3, 5] and Vectorland consisting of the interval [2, 8]:

<image>

As Vectorland completely contains Arrayland, the legend is true. It can also be shown that the legend is true for the pair \{2, -3\}, for a total of two pairs.

In the second sample, the only pair is \{3, 6\}, and the situation looks as follows:

<image>

Note that even though Arrayland and Vectorland share 3 as endpoint, we still consider Arrayland to be completely inside of Vectorland.
```python
num = int(input())

data = [abs(int(i)) for i in input().split()]
data.sort()

def bins(a, b, n):
    if a == b:
        if data[a] <= n:
            return a+1
        else:
            return a
    else:
        m = (a+b)//2
        if data[m] <= n:
            return bins(m+1,b,n)
        else:
            return bins(a, m, n)

sum = 0
#prev = 0
ind = 0
for i in range(num):
    while ind < num and data[ind] <= 2*data[i]:
        ind += 1

    
    
    #prev = bins(prev, num-1, 2*data[i]) - 1
    sum += ind - i - 1
    #print(2*data[i] ,bins(i, num-1, 2*data[i]), bins(i, num-1, 2*data[i]) - i - 1)


print(sum)


#data = [1,2,3, 4,5,6,7,23]

#print(bins(1,6,3))
```