import java.util.*;

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", "");
        if (S.length() == 0) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
}
 import java.util.*; util.* java 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", "");
        if (S.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 S = sc.next();
        S = S.replaceAll("eraser", "");
        S = S.replaceAll("erase", "");
        S = S.replaceAll("dreamer", "");
        S = S.replaceAll("dream", "");
        if (S.length() == 0) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    } main {
        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", "");
        if (S.length() == 0) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc S = S.replaceAll("eraser", "") S S.replaceAll("eraser", "") S.replaceAll S "eraser" "" S = S.replaceAll("erase", "") S S.replaceAll("erase", "") S.replaceAll S "erase" "" S = S.replaceAll("dreamer", "") S S.replaceAll("dreamer", "") S.replaceAll S "dreamer" "" S = S.replaceAll("dream", "") S S.replaceAll("dream", "") S.replaceAll S "dream" "" if (S.length() == 0) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        } S.length() == 0 S.length() S.length S 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
import java.util.*;

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

