func main()
	var s: []char :: cui@input()
	var n: int :: 0
	var ans: int :: 1
	if(^s > 2)
		do n :: s.sub(^s - 2, -1).toInt(&)
	else
		do n :: s.toInt(&)
		if(n = 1 | n = 4)
			do ans :: -1
		end if
	end if
	if(n % 4 = 2)
		do ans :: -1
	end if
	do cui@print("\{ans}\n")
end func