import java.util.Scanner;

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

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