N = int(input())
A = list(map(int,input().split()))

from collections import defaultdict
dic = defaultdict(int)

for a in A:
  dic[a] += 1
  
dic = sorted(dic.items(), key = lambda x:x[0], reverse = True)

rate = 1 # 条件を満たす取り出し方
for number, cnt in dic:
  # rest個の中からcnt個を引く
  for c in range(cnt, 0, -1):
    rate *= c

# 全ての取り出し方
alls = 1
for i in range(1, N + 1):
  alls *= i
  
print(alls // rate)