func main()
	var n: int :: cui@inputInt()
	if(n = 0)
		do cui@print("0\n")
		ret
	end if
	var s: []char :: #[n]char
	for i(0, n - 1)
		do s[i] :: "142857"[i % 6]
	end for
	do cui@print("0.\{s}\n")
end func