while True:
	n = int(raw_input())
	if n == 0:
		break
	li = raw_input().strip().split()
	
	lis = []
	for v in li:
		v = list(v)
		v.sort()
		lis.append(int("".join(v)))

	lic = []
	lid = map(int,li)
	for i in range(n):
		if(lis.count(lis[i]) == 1):
			lic.append(lid[i])
		
	if len(lic) == 0:
		print "None"
	else:
		lic.sort()
		for v in lic:
			print v,
		print