You are given a set S of integers between -30000 and 30000 (inclusive).

Find the total number of sextuples (a, b, c, d, e, f): a, b, c, d, e, f ∈ S; d ≠ 0  that satisfy:

Input

The first line contains integer N (1 ≤ N ≤ 100), the size of a set S.

Elements of S are given in the next N lines, one integer per line. Given numbers will be distinct.

Output

Output the total number of plausible sextuples.

Examples

Input:
1
1

Output:
1

Input:
2
2
3

Output:
4

Input:
2
-1
1

Output:
24

Input:
3
5
7
10

Output:
10