func main()
	var s: []char :: cui@input()
	var b: bit8 :: 1b8
	for i(0, ^s - 1)
		do b :* ((i % 2 = 0) $ bit8.xor((s[i] = ' ') $ bit8))
	end for
	var ans: bool :: b $ bool
	do cui@print(ans ?("Yes\n", "No\n"))
end func