import java.util.*;
import java.io.*;
 
public class Main {
    static String[] word = {"dream", "dreamer", "erase", "eraser"};
    static int[] wordlen = {5,7,5,6};
    public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner(System.in);
        String s = sc.next();
        int nowIndex = s.length();
        while(nowIndex > 0){
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        }
        System.out.println(nowIndex == 0 ? "YES" : "NO");
    }
}

class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;
    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken("\n");
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
         return Double.parseDouble(next());
    }

    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    } 
} import java.util.*; util.* java import java.io.*; io.* java public class Main {
    static String[] word = {"dream", "dreamer", "erase", "eraser"};
    static int[] wordlen = {5,7,5,6};
    public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner(System.in);
        String s = sc.next();
        int nowIndex = s.length();
        while(nowIndex > 0){
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        }
        System.out.println(nowIndex == 0 ? "YES" : "NO");
    }
} Main static String[] word = {"dream", "dreamer", "erase", "eraser"}; word {"dream", "dreamer", "erase", "eraser"} "dream" "dreamer" "erase" "eraser" static int[] wordlen = {5,7,5,6}; wordlen {5,7,5,6} 5 7 5 6 public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner(System.in);
        String s = sc.next();
        int nowIndex = s.length();
        while(nowIndex > 0){
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        }
        System.out.println(nowIndex == 0 ? "YES" : "NO");
    } main {
        FastScanner sc = new FastScanner(System.in);
        String s = sc.next();
        int nowIndex = s.length();
        while(nowIndex > 0){
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        }
        System.out.println(nowIndex == 0 ? "YES" : "NO");
    } FastScanner sc = new FastScanner(System.in); sc new FastScanner(System.in) String s = sc.next(); s sc.next() sc.next sc int nowIndex = s.length(); nowIndex s.length() s.length s while(nowIndex > 0){
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        } nowIndex > 0 nowIndex 0 {
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        } boolean flg = false; flg false for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            } int i = 0; int i = 0; i 0 i < 4 i 4 i++ i++ i {
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            } {
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            } if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                } nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i]) nowIndex >= wordlen[i] nowIndex wordlen[i] wordlen i s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i]) s.substring(nowIndex-wordlen[i],nowIndex).equals s.substring(nowIndex-wordlen[i],nowIndex) s.substring s nowIndex-wordlen[i] nowIndex wordlen[i] wordlen i nowIndex word[i] word i {
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                } nowIndex -= wordlen[i] nowIndex wordlen[i] wordlen i flg = true flg true break; if(!flg){
                break;
            } !flg flg {
                break;
            } break; System.out.println(nowIndex == 0 ? "YES" : "NO") System.out.println System.out System System.out nowIndex == 0 ? "YES" : "NO" nowIndex == 0 nowIndex 0 "YES" "NO" String[] args args class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;
    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken("\n");
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
         return Double.parseDouble(next());
    }

    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    } 
} FastScanner private BufferedReader reader = null; reader null private StringTokenizer tokenizer = null; tokenizer null public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    } FastScanner {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    } reader = new BufferedReader(new InputStreamReader(in)) reader new BufferedReader(new InputStreamReader(in)) tokenizer = null tokenizer null InputStream in in public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    } next {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    } if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            } catch (IOException e) {
                throw new RuntimeException(e);
            } IOException e {
                throw new RuntimeException(e);
            } throw new RuntimeException(e); new RuntimeException(e) {
                tokenizer = new StringTokenizer(reader.readLine());
            } tokenizer = new StringTokenizer(reader.readLine()) tokenizer new StringTokenizer(reader.readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken("\n");
    } nextLine {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken("\n");
    } if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        } try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            } catch (IOException e) {
                throw new RuntimeException(e);
            } IOException e {
                throw new RuntimeException(e);
            } throw new RuntimeException(e); new RuntimeException(e) {
                return reader.readLine();
            } return reader.readLine(); reader.readLine() reader.readLine reader return tokenizer.nextToken("\n"); tokenizer.nextToken("\n") tokenizer.nextToken tokenizer "\n" public long nextLong() {
        return Long.parseLong(next());
    } nextLong {
        return Long.parseLong(next());
    } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next public int nextInt() {
        return Integer.parseInt(next());
    } nextInt {
        return Integer.parseInt(next());
    } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next public double nextDouble() {
         return Double.parseDouble(next());
    } nextDouble {
         return Double.parseDouble(next());
    } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    } nextIntArray {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    } int[] a = new int[n]; a new int[n] n for (int i = 0; i < n; i++)
            a[i] = nextInt(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = nextInt(); a[i] = nextInt() a[i] a i nextInt() nextInt return a; a int n n public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    } nextLongArray {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    } long[] a = new long[n]; a new long[n] n for (int i = 0; i < n; i++)
            a[i] = nextLong(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = nextLong(); a[i] = nextLong() a[i] a i nextLong() nextLong return a; a int n n public class Main {
    static String[] word = {"dream", "dreamer", "erase", "eraser"};
    static int[] wordlen = {5,7,5,6};
    public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner(System.in);
        String s = sc.next();
        int nowIndex = s.length();
        while(nowIndex > 0){
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        }
        System.out.println(nowIndex == 0 ? "YES" : "NO");
    }
} public class Main {
    static String[] word = {"dream", "dreamer", "erase", "eraser"};
    static int[] wordlen = {5,7,5,6};
    public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner(System.in);
        String s = sc.next();
        int nowIndex = s.length();
        while(nowIndex > 0){
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        }
        System.out.println(nowIndex == 0 ? "YES" : "NO");
    }
} Main
import java.util.*;
import java.io.*;
 
public class Main {
    static String[] word = {"dream", "dreamer", "erase", "eraser"};
    static int[] wordlen = {5,7,5,6};
    public static void main(String[] args) throws Exception {
        FastScanner sc = new FastScanner(System.in);
        String s = sc.next();
        int nowIndex = s.length();
        while(nowIndex > 0){
            boolean flg = false;
            for(int i = 0; i < 4; i++){
                if(nowIndex >= wordlen[i] && s.substring(nowIndex-wordlen[i],nowIndex).equals(word[i])){
                    nowIndex -= wordlen[i];
                    flg = true;
                    break;
                }
            }
            if(!flg){
                break;
            }
        }
        System.out.println(nowIndex == 0 ? "YES" : "NO");
    }
}

class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;
    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken("\n");
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
         return Double.parseDouble(next());
    }

    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    } 
}
