    import java.util.Scanner;
     
    class Main{
     
        public static void main(String[] args){
            Scanner sc = new Scanner(System.in);
            String S = sc.nextLine();
            String T = "";
            String[] str = {"dream","dreamer","erase","eraser"};
     
            
            S = S.replace("eraser", "").replace("erase", "").replace("dreamer", "").replace("dream", "");
     
            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