import math
n = int(input())
a = list(map(int,input().split()))
a.sort()
ans_u = []
ans_d = []
for idx,num in enumerate(a):
    same_n = 0
    for i in range(idx+1,n):
        if num == a[i]:
            same_n += 1
    ans_u.append(same_n + 1)
    ans_d.append(n-idx)

ans = math.prod(ans_d) / math.prod(ans_u)

print(int(ans))