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
 *
 * @author mikit
 */
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);
        CDaydream solver = new CDaydream();
        solver.solve(1, in, out);
        out.close();
    }

    static class CDaydream {
        public static final String[] STRINGS = {"esare", "resare", "maerd", "remaerd"};

        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String s = new StringBuilder(in.next()).reverse().toString();
            int i = 0;
            outer:
            while (i < s.length()) {
                for (String k : STRINGS) {
                    if (s.startsWith(k, i)) {
                        i += k.length();
                        continue outer;
                    }
                }
                out.println("NO");
                return;
            }
            out.println("YES");
        }

    }
}
 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);
        CDaydream solver = new CDaydream();
        solver.solve(1, in, out);
        out.close();
    }

    static class CDaydream {
        public static final String[] STRINGS = {"esare", "resare", "maerd", "remaerd"};

        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String s = new StringBuilder(in.next()).reverse().toString();
            int i = 0;
            outer:
            while (i < s.length()) {
                for (String k : STRINGS) {
                    if (s.startsWith(k, i)) {
                        i += k.length();
                        continue outer;
                    }
                }
                out.println("NO");
                return;
            }
            out.println("YES");
        }

    }
} 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);
        CDaydream solver = new CDaydream();
        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);
        CDaydream solver = new CDaydream();
        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) CDaydream solver = new CDaydream(); solver new CDaydream() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class CDaydream {
        public static final String[] STRINGS = {"esare", "resare", "maerd", "remaerd"};

        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String s = new StringBuilder(in.next()).reverse().toString();
            int i = 0;
            outer:
            while (i < s.length()) {
                for (String k : STRINGS) {
                    if (s.startsWith(k, i)) {
                        i += k.length();
                        continue outer;
                    }
                }
                out.println("NO");
                return;
            }
            out.println("YES");
        }

    } CDaydream public static final String[] STRINGS = {"esare", "resare", "maerd", "remaerd"}; STRINGS {"esare", "resare", "maerd", "remaerd"} "esare" "resare" "maerd" "remaerd" public void solve(int testNumber, Scanner in, PrintWriter out) {
            String s = new StringBuilder(in.next()).reverse().toString();
            int i = 0;
            outer:
            while (i < s.length()) {
                for (String k : STRINGS) {
                    if (s.startsWith(k, i)) {
                        i += k.length();
                        continue outer;
                    }
                }
                out.println("NO");
                return;
            }
            out.println("YES");
        } solve {
            String s = new StringBuilder(in.next()).reverse().toString();
            int i = 0;
            outer:
            while (i < s.length()) {
                for (String k : STRINGS) {
                    if (s.startsWith(k, i)) {
                        i += k.length();
                        continue outer;
                    }
                }
                out.println("NO");
                return;
            }
            out.println("YES");
        } String s = new StringBuilder(in.next()).reverse().toString(); s new StringBuilder(in.next()).reverse().toString() new StringBuilder(in.next()).reverse().toString new StringBuilder(in.next()).reverse() new StringBuilder(in.next()).reverse new StringBuilder(in.next()) int i = 0; i 0 out.println("YES") out.println out "YES" 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);
        CDaydream solver = new CDaydream();
        solver.solve(1, in, out);
        out.close();
    }

    static class CDaydream {
        public static final String[] STRINGS = {"esare", "resare", "maerd", "remaerd"};

        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String s = new StringBuilder(in.next()).reverse().toString();
            int i = 0;
            outer:
            while (i < s.length()) {
                for (String k : STRINGS) {
                    if (s.startsWith(k, i)) {
                        i += k.length();
                        continue outer;
                    }
                }
                out.println("NO");
                return;
            }
            out.println("YES");
        }

    }
} 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);
        CDaydream solver = new CDaydream();
        solver.solve(1, in, out);
        out.close();
    }

    static class CDaydream {
        public static final String[] STRINGS = {"esare", "resare", "maerd", "remaerd"};

        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String s = new StringBuilder(in.next()).reverse().toString();
            int i = 0;
            outer:
            while (i < s.length()) {
                for (String k : STRINGS) {
                    if (s.startsWith(k, i)) {
                        i += k.length();
                        continue outer;
                    }
                }
                out.println("NO");
                return;
            }
            out.println("YES");
        }

    }
} 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
 *
 * @author mikit
 */
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);
        CDaydream solver = new CDaydream();
        solver.solve(1, in, out);
        out.close();
    }

    static class CDaydream {
        public static final String[] STRINGS = {"esare", "resare", "maerd", "remaerd"};

        public void solve(int testNumber, Scanner in, PrintWriter out) {
            String s = new StringBuilder(in.next()).reverse().toString();
            int i = 0;
            outer:
            while (i < s.length()) {
                for (String k : STRINGS) {
                    if (s.startsWith(k, i)) {
                        i += k.length();
                        continue outer;
                    }
                }
                out.println("NO");
                return;
            }
            out.println("YES");
        }

    }
}

