import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class Main {
    public static void main(String args[]) throws IOException{
        BufferedReader buff = null;
        buff = new BufferedReader(new InputStreamReader(System.in));
        String s = buff.readLine();
        s = s.replaceAll("eraser","").replaceAll("erase","").replaceAll("dreamer","").replaceAll("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