import java.util.Scanner;

class Main{
	public static void main(String arg[]) {
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		sc.close();
		
		S = S.replaceAll("eraser",  "-");
        S = S.replaceAll("erase",   "-");
        S = S.replaceAll("dreamer", "-");
        S = S.replaceAll("dream",   "-");
        S = S.replaceAll("-", "");
        if (S.length() == 0) {
        	System.out.println("YES");
        }else {
            System.out.println("NO");
        }
	}
} import java.util.Scanner; Scanner java.util class Main{
	public static void main(String arg[]) {
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		sc.close();
		
		S = S.replaceAll("eraser",  "-");
        S = S.replaceAll("erase",   "-");
        S = S.replaceAll("dreamer", "-");
        S = S.replaceAll("dream",   "-");
        S = S.replaceAll("-", "");
        if (S.length() == 0) {
        	System.out.println("YES");
        }else {
            System.out.println("NO");
        }
	}
} Main public static void main(String arg[]) {
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		sc.close();
		
		S = S.replaceAll("eraser",  "-");
        S = S.replaceAll("erase",   "-");
        S = S.replaceAll("dreamer", "-");
        S = S.replaceAll("dream",   "-");
        S = S.replaceAll("-", "");
        if (S.length() == 0) {
        	System.out.println("YES");
        }else {
            System.out.println("NO");
        }
	} main {
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		sc.close();
		
		S = S.replaceAll("eraser",  "-");
        S = S.replaceAll("erase",   "-");
        S = S.replaceAll("dreamer", "-");
        S = S.replaceAll("dream",   "-");
        S = S.replaceAll("-", "");
        if (S.length() == 0) {
        	System.out.println("YES");
        }else {
            System.out.println("NO");
        }
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.nextLine(); S sc.nextLine() sc.nextLine sc sc.close() sc.close 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" "-" S = S.replaceAll("-", "") S S.replaceAll("-", "") S.replaceAll S "-" "" if (S.length() == 0) {
        	System.out.println("YES");
        }else {
            System.out.println("NO");
        } S.length() == 0 S.length() S.length S 0 {
        	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 arg[] arg
import java.util.Scanner;

class Main{
	public static void main(String arg[]) {
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		sc.close();
		
		S = S.replaceAll("eraser",  "-");
        S = S.replaceAll("erase",   "-");
        S = S.replaceAll("dreamer", "-");
        S = S.replaceAll("dream",   "-");
        S = S.replaceAll("-", "");
        if (S.length() == 0) {
        	System.out.println("YES");
        }else {
            System.out.println("NO");
        }
	}
}