// No.908 うしたぷにきあくん文字列
package main

import "fmt"

func main() {
	var s string
	fmt.Scan(&s)

	ans := "Yes"
	for i, r := range s {
		if i%2 == 0 {
			if string(r) == " " {
				ans = "No"
				break
			}
		} else {
			if string(r) != " " {
				ans = "No"
				break
			}
		}
	}
	fmt.Println(ans)
}