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 PyPy3 (7.3.0) (judge verdict: Accepted)

# -*- coding: utf-8 -*-
 
## Library
 
import sys
from fractions import gcd
import math
from math import ceil,floor
import collections
from collections import Counter
import itertools
import copy

## input
 
# N=int(input())
# A,B,C,D=map(int, input().split())
# S = input()
# yoko = list(map(int, input().split()))
# tate = [int(input()) for _ in range(N)]
# N, M = map(int,input().split()) 
#    P = [list(map(int,input().split())) for i in range(M)]
#    S = []
#    for _ in range(N):
#        S.append(list(input()))

def combination(n,r):
    return int(math.factorial(n)/math.factorial(r)/math.factorial(n-r))
 
N=int(input())
L = list(map(int, input().split()))

L.sort()

if N<=2 or len(Counter(L))<3:
    print(0)
    sys.exit()

tmp = list(itertools.combinations(L,3))
ans = 0


for i in range(len(tmp)):
    if tmp[i][0] == tmp[i][1] or tmp[i][1] == tmp[i][2] or tmp[i][2] == tmp[i][0] or tmp[i][0] + tmp[i][1] <= tmp[i][2]:
        continue
    else:
        ans += 1

print(ans)