import java.util.Scanner;
 
public class Main{
	public static void main(String args[])throws Exception{
 
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		S = S.replaceAll("eraser","");
		S = S.replaceAll("erase","");
		S = S.replaceAll("dreamer","");
		S = S.replaceAll("dream","");
		if(S.equals("")) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
	}
} import java.util.Scanner; Scanner java.util public class Main{
	public static void main(String args[])throws Exception{
 
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		S = S.replaceAll("eraser","");
		S = S.replaceAll("erase","");
		S = S.replaceAll("dreamer","");
		S = S.replaceAll("dream","");
		if(S.equals("")) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
	}
} Main public static void main(String args[])throws Exception{
 
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		S = S.replaceAll("eraser","");
		S = S.replaceAll("erase","");
		S = S.replaceAll("dreamer","");
		S = S.replaceAll("dream","");
		if(S.equals("")) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
	} main {
 
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		S = S.replaceAll("eraser","");
		S = S.replaceAll("erase","");
		S = S.replaceAll("dreamer","");
		S = S.replaceAll("dream","");
		if(S.equals("")) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc S = S.replaceAll("eraser","") S S.replaceAll("eraser","") S.replaceAll S "eraser" "" S = S.replaceAll("erase","") S S.replaceAll("erase","") S.replaceAll S "erase" "" S = S.replaceAll("dreamer","") S S.replaceAll("dreamer","") S.replaceAll S "dreamer" "" S = S.replaceAll("dream","") S S.replaceAll("dream","") S.replaceAll S "dream" "" if(S.equals("")) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		} S.equals("") S.equals S "" {
			System.out.println("YES");
		} System.out.println("YES") System.out.println System.out System System.out "YES" {
			System.out.println("NO");
		} System.out.println("NO") System.out.println System.out System System.out "NO" String args[] args public class Main{
	public static void main(String args[])throws Exception{
 
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		S = S.replaceAll("eraser","");
		S = S.replaceAll("erase","");
		S = S.replaceAll("dreamer","");
		S = S.replaceAll("dream","");
		if(S.equals("")) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
	}
} public class Main{
	public static void main(String args[])throws Exception{
 
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		S = S.replaceAll("eraser","");
		S = S.replaceAll("erase","");
		S = S.replaceAll("dreamer","");
		S = S.replaceAll("dream","");
		if(S.equals("")) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
	}
} Main
import java.util.Scanner;
 
public class Main{
	public static void main(String args[])throws Exception{
 
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		S = S.replaceAll("eraser","");
		S = S.replaceAll("erase","");
		S = S.replaceAll("dreamer","");
		S = S.replaceAll("dream","");
		if(S.equals("")) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
	}
}