import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();

		int i = 0;
        for ( ; i < s.length(); i++) {
    	    String c = String.valueOf(s.charAt(i));
            if (i % 2 == 0) {
      	        if (c.equals(" ")) {
				    break;
			    }
            }
        }

		if (i == s.length()) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

	}
}