import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		StringBuilder sb = new StringBuilder(S);
		String ans = S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", "");
		System.out.println(ans.equals("") ? "YES" :"NO");
	}
} import java.util.Scanner; Scanner java.util public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		StringBuilder sb = new StringBuilder(S);
		String ans = S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", "");
		System.out.println(ans.equals("") ? "YES" :"NO");
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		StringBuilder sb = new StringBuilder(S);
		String ans = S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", "");
		System.out.println(ans.equals("") ? "YES" :"NO");
	} main {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		StringBuilder sb = new StringBuilder(S);
		String ans = S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", "");
		System.out.println(ans.equals("") ? "YES" :"NO");
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc StringBuilder sb = new StringBuilder(S); sb new StringBuilder(S) String ans = S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", ""); ans S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", "") S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "") S.replace("eraser", "")
				.replace("erase", "")
				.replace S.replace("eraser", "")
				.replace("erase", "") S.replace("eraser", "")
				.replace S.replace("eraser", "") S.replace S "eraser" "" "erase" "" "dreamer" "" "dream" "" System.out.println(ans.equals("") ? "YES" :"NO") System.out.println System.out System System.out ans.equals("") ? "YES" :"NO" ans.equals("") ans.equals ans "" "YES" "NO" String[] args args public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		StringBuilder sb = new StringBuilder(S);
		String ans = S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", "");
		System.out.println(ans.equals("") ? "YES" :"NO");
	}
} public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		StringBuilder sb = new StringBuilder(S);
		String ans = S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", "");
		System.out.println(ans.equals("") ? "YES" :"NO");
	}
} Main
import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		StringBuilder sb = new StringBuilder(S);
		String ans = S.replace("eraser", "")
				.replace("erase", "")
				.replace("dreamer", "")
				.replace("dream", "");
		System.out.println(ans.equals("") ? "YES" :"NO");
	}
}