import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.util.*;
import java.util.stream.Stream;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String line = sc.next();
        String[] list = {"eraser", "erase", "dreamer", "dream"};

        for(String l: list){
            line = line.replaceAll(l, "");
        }

        if(line.length() != 0){
            System.out.println("NO");
        } else {
            System.out.println("YES");
        }
    }
}

/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