from collections import Counter
from sys import stdin


def main():
    input = lambda: stdin.readline()[:-1]
    N = int(input())
    A = map(int, input().split())

    nums = sorted(Counter(A).items())
    one, two = 0, 0
    if nums[0][0] == 1:
        one = nums[0][1]
    if len(nums) > 1 and nums[1][0] == 2:
        two = nums[1][1]
    other = N - one - two

    ans = (one - 1) * one // 2 * 2
    ans += one * two * 3
    ans += one * other * 2
    n = N - one
    ans += (n - 1) * n // 2
    print(ans)


main()