import sys
def main():
	N = int(input())
	li = list(map(int,input().split()))
	total = 0

	for i in range(len(li)):
		total += li[i]
		

	for i in range(len(li)):
		if(li[i] > (total / 2)):
			print("out")
			sys.exit()
	
	if((total % 2) != 0):
		print("out")
		sys.exit()

	print("ok")

	
if __name__ == '__main__':
	main()