import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        C solver = new C();
        solver.solve(1, in, out);
        out.close();
    }

    static class C {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String S = in.next();
            S = S.replaceAll("eraser", "-");
            S = S.replaceAll("erase", "-");
            S = S.replaceAll("dreamer", "-");
            S = S.replaceAll("dream", "-");
            S = S.replaceAll("-", "");
            if (S.length() == 0)
                out.println("YES");
            else
                out.println("NO");
        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        C solver = new C();
        solver.solve(1, in, out);
        out.close();
    }

    static class C {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String S = in.next();
            S = S.replaceAll("eraser", "-");
            S = S.replaceAll("erase", "-");
            S = S.replaceAll("dreamer", "-");
            S = S.replaceAll("dream", "-");
            S = S.replaceAll("-", "");
            if (S.length() == 0)
                out.println("YES");
            else
                out.println("NO");
        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        C solver = new C();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        C solver = new C();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) C solver = new C(); solver new C() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class C {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String S = in.next();
            S = S.replaceAll("eraser", "-");
            S = S.replaceAll("erase", "-");
            S = S.replaceAll("dreamer", "-");
            S = S.replaceAll("dream", "-");
            S = S.replaceAll("-", "");
            if (S.length() == 0)
                out.println("YES");
            else
                out.println("NO");
        }

    } C public void solve(int testNumber, Scanner in, PrintWriter out) {
            String S = in.next();
            S = S.replaceAll("eraser", "-");
            S = S.replaceAll("erase", "-");
            S = S.replaceAll("dreamer", "-");
            S = S.replaceAll("dream", "-");
            S = S.replaceAll("-", "");
            if (S.length() == 0)
                out.println("YES");
            else
                out.println("NO");
        } solve {
            String S = in.next();
            S = S.replaceAll("eraser", "-");
            S = S.replaceAll("erase", "-");
            S = S.replaceAll("dreamer", "-");
            S = S.replaceAll("dream", "-");
            S = S.replaceAll("-", "");
            if (S.length() == 0)
                out.println("YES");
            else
                out.println("NO");
        } String S = in.next(); S in.next() in.next in 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)
                out.println("YES");
            else
                out.println("NO"); S.length() == 0 S.length() S.length S 0 out.println("YES") out.println out "YES" out.println("NO") out.println out "NO" int testNumber testNumber Scanner in in PrintWriter out out public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        C solver = new C();
        solver.solve(1, in, out);
        out.close();
    }

    static class C {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String S = in.next();
            S = S.replaceAll("eraser", "-");
            S = S.replaceAll("erase", "-");
            S = S.replaceAll("dreamer", "-");
            S = S.replaceAll("dream", "-");
            S = S.replaceAll("-", "");
            if (S.length() == 0)
                out.println("YES");
            else
                out.println("NO");
        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        C solver = new C();
        solver.solve(1, in, out);
        out.close();
    }

    static class C {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String S = in.next();
            S = S.replaceAll("eraser", "-");
            S = S.replaceAll("erase", "-");
            S = S.replaceAll("dreamer", "-");
            S = S.replaceAll("dream", "-");
            S = S.replaceAll("-", "");
            if (S.length() == 0)
                out.println("YES");
            else
                out.println("NO");
        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        C solver = new C();
        solver.solve(1, in, out);
        out.close();
    }

    static class C {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String S = in.next();
            S = S.replaceAll("eraser", "-");
            S = S.replaceAll("erase", "-");
            S = S.replaceAll("dreamer", "-");
            S = S.replaceAll("dream", "-");
            S = S.replaceAll("-", "");
            if (S.length() == 0)
                out.println("YES");
            else
                out.println("NO");
        }

    }
}

