#!usr/bin/env python3
from collections import defaultdict, deque
from heapq import heappush, heappop
from itertools import permutations, accumulate
import sys
import math
import bisect
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def I(): return int(sys.stdin.readline())
def IR(n):
    return [I() for _ in range(n)]
def LIR(n):
    return [LI() for _ in range(n)]

sys.setrecursionlimit(1000000)
mod = 1000000007

def main():
    n = I()
    a = LI()
    a.sort()
    count = defaultdict(lambda : 0)
    for i in a:
        count[i] += 1
    count = list(count.items())
    count.sort()
    p = 1
    q = 1
    res = n
    for _, j in count:
        for i in range(1,j+1):
            p *= i
            q *= n
            n -= 1
    print(q//p)
    return


if __name__ == "__main__":
    main()