import java.util.*;
public class Main {
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
String s=sc.next();
s=s.replaceAll("eraser", "-");
s=s.replaceAll("erase", "-");
s=s.replaceAll("dreamer", "-");
s=s.replaceAll("dream", "-");
s=s.replaceAll("-","");
if(s.equals("")){System.out.println("YES");}else{System.out.println("NO");}
}}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz