ABCDEF - ABCDEF

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

Find the total number of sextuples  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



Added by:Luka Kalinovcic
Date:2009-07-13
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ERL JS-RHINO NODEJS PERL6 VB.NET
Resource:own problem

hide comments
2017-12-01 09:12:37
lower_bound and upper-bound !!!
2017-10-29 23:48:44
Beware d can't be zero ! ac in 2nd go :)
2017-09-23 18:50:38
Nice one..lower bound and upper bound will help O(n^3) is acceptable.
2017-08-25 22:00:10
nice problem use unordered_map stl
2017-08-22 11:20:37
Hint: Use only one unordered_map.
2017-08-19 03:48:06
use sort, AC in one go, O(3*(N^3)*logN) , but I don't know how to use hash.
2017-07-07 15:38:21
use hash, AC in one go
2017-06-20 12:48:13
can anyone explain the problem clearly??
2017-06-17 12:25:23
shit this d gives me 3 WA !!
A standard classic problem !!
2017-05-29 18:16:17
Great Problem!
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