import java.util.*;

class Main{
	public static void main(String[] $) {
		Scanner s=new Scanner(System.in);
		char[]c=s.nextLine().toCharArray();
		for(int i=0;i<c.length;++i) {
			if(i%2==1^c[i]==' ') {
				System.out.println("No");
				return;
			}
		}
		System.out.println("Yes");
	}
}