import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.nextLine();
    s = s.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("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) {
    Scanner sc = new Scanner(System.in);
    String s = sc.nextLine();
    s = s.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("dream", "");
    if (s.equals("")) {
      System.out.println("YES");
    } else {
      System.out.println("NO");
    }
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.nextLine();
    s = s.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("dream", "");
    if (s.equals("")) {
      System.out.println("YES");
    } else {
      System.out.println("NO");
    }
  } main {
    Scanner sc = new Scanner(System.in);
    String s = sc.nextLine();
    s = s.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("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.nextLine(); s sc.nextLine() sc.nextLine sc s = s.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("dream", "") s 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" "" 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) {
    Scanner sc = new Scanner(System.in);
    String s = sc.nextLine();
    s = s.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("dream", "");
    if (s.equals("")) {
      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 s = sc.nextLine();
    s = s.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("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) {
    Scanner sc = new Scanner(System.in);
    String s = sc.nextLine();
    s = s.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("dream", "");
    if (s.equals("")) {
      System.out.println("YES");
    } else {
      System.out.println("NO");
    }
  }
}
