from math import factorial

def hex_fact_trailing_zeros(n):
	num_2s = 0
	for i in range(1, 20):
		p = 2 ** i
		num_2s += n / p
	return num_2s / 4

def test():
	for i in range(0, 2000):
		f = factorial(i)
		z = hex_fact_trailing_zeros(i)
		print i
		if f % (16 ** z) != 0:
			print "too high ", i
			return
		if f % (16 ** (z+1)) == 0:
			print "too low ", i
			return
	print "ok!"

test()