func main()
	var s: []char :: cui@input()
	var cnt: dict<char, int> :: #dict<char, int>
	for i(0, ^s - 1)
		var c: char :: s[i]
		var num: int :: cnt.get(c, &)
		do cnt.add(c, num + 1)
		if(num = 2)
			do cui@print("Impossible\n")
			ret
		end if
	end for
	if(^cnt <> 7)
		do cui@print("Impossible\n")
		ret
	end if
	
	do cnt.forEach(f, null)
	
	func f(key: char, val: int, data: kuin@Class): bool
		if(val = 1)
			do cui@print("\{key}\n")
		end if
		ret true
	end func
end func