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.length() == 0) System.out.println("YES");
        else System.out.println("NO");
    }
} import java.util.*; util.* java 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.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",   "-");
        S = S.replaceAll("-", "");
        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",   "-");
        S = S.replaceAll("-", "");
        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" "-" S = S.replaceAll("-", "") S S.replaceAll("-", "") S.replaceAll S "-" "" 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 System.out System System.out "YES" System.out.println("NO") System.out.println System.out System System.out "NO" String[] args args 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.length() == 0) System.out.println("YES");
        else System.out.println("NO");
    }
} 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.length() == 0) System.out.println("YES");
        else System.out.println("NO");
    }
} Main
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.length() == 0) System.out.println("YES");
        else System.out.println("NO");
    }
}