Problem:
Score : 200 points

Problem Statement

We have sticks numbered 1, \cdots, N. The length of Stick i (1 \leq i \leq N) is L_i.

In how many ways can we choose three of the sticks with different lengths that can form a triangle?

That is, find the number of triples of integers (i, j, k) (1 \leq i < j < k \leq N) that satisfy both of the following conditions:

L_i, L_j, and L_k are all different.

There exists a triangle whose sides have lengths L_i, L_j, and L_k.

Constraints

1 \leq N \leq 100

1 \leq L_i \leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
L_1 L_2 \cdots L_N

Output

Print the number of ways to choose three of the sticks with different lengths that can form a triangle.

Sample Input 1

5
4 4 9 7 5

Sample Output 1

5

The following five triples (i, j, k) satisfy the conditions: (1, 3, 4), (1, 4, 5), (2, 3, 4), (2, 4, 5), and (3, 4, 5).

Sample Input 2

6
4 5 4 3 3 5

Sample Output 2

8

We have two sticks for each of the lengths 3, 4, and 5. To satisfy the first condition, we have to choose one from each length.

There is a triangle whose sides have lengths 3, 4, and 5, so we have 2 ^ 3 = 8 triples (i, j, k) that satisfy the conditions.

Sample Input 3

10
9 4 6 1 9 6 10 6 6 8

Sample Output 3

39

Sample Input 4

2
1 1

Sample Output 4

0

No triple (i, j, k) satisfies 1 \leq i < j < k \leq N, so we should print 0.

Solution in Python (3.8.2) (judge verdict: Accepted)

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# FileName: 	B
# CreatedDate:  2020-08-15 20:38:49 +0900
# LastModified: 2020-08-15 21:11:14 +0900
#


import os
import sys
# import numpy as np
# import pandas as pd


def main():
    N = int(input())
    L = sorted(list(map(int, input().split())))
    cnt = 0
    for i in range(N-2):
        for j in range(i+1, N-1):
            for k in range(j+1, N):
                if L[k] < L[i] + L[j] and L[k] != L[i] and L[k] != L[j] and L[i] != L[j]:
                    cnt += 1
    print(cnt)


if __name__ == "__main__":
    main()