N = int(input())
A = [int(i)-1 for i in input().split()]
#s = [[int(j) for j in input().split()] for i in range(N)]

d = dict([(i,0) for i in range(100)])
for a in A:
    d[a]+=1

res = 0
for i in range(100):
    for j in range(i+1,100):
        for k in range(j+1,100):
            res += d[i] * d[j] * d[k]
print(res)