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