def main():
	s = input()
	s = sorted(s)
	c=""
	for i in range(6):
		print(s)
		if s[0] == s[1]:
			if s[0] == s[2]:
				print("Impossible\n")
				return
			else:
				del s[:2]
		elif c == "":
			c = s.pop(0)
		else:
			print("Impossible\n")
			return
	if c=="":
		print(s[0])
	else:
		print(c)


main()