import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;

/**
 * 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;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		Task solver = new Task();
		solver.solve(1, in, out);
		out.close();
	}

	static class Task {
		public void solve(int testNumber, InputReader 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) {
	            System.out.println("YES");
	        }else{
	            System.out.println("NO");
			}
		}
	}
	
	static class InputReader {
		public BufferedReader reader;
		public StringTokenizer tokenizer;

		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}

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

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

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

	static class Task {
		public void solve(int testNumber, InputReader 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) {
	            System.out.println("YES");
	        }else{
	            System.out.println("NO");
			}
		}
	}
	
	static class InputReader {
		public BufferedReader reader;
		public StringTokenizer tokenizer;

		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}

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

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

	}
} Main public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		Task solver = new Task();
		solver.solve(1, in, out);
		out.close();
	} main {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		Task solver = new Task();
		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 InputReader in = new InputReader(inputStream); in new InputReader(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) Task solver = new Task(); solver new Task() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class Task {
		public void solve(int testNumber, InputReader 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) {
	            System.out.println("YES");
	        }else{
	            System.out.println("NO");
			}
		}
	} Task public void solve(int testNumber, InputReader 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) {
	            System.out.println("YES");
	        }else{
	            System.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) {
	            System.out.println("YES");
	        }else{
	            System.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) {
	            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" int testNumber testNumber InputReader in in PrintWriter out out static class InputReader {
		public BufferedReader reader;
		public StringTokenizer tokenizer;

		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}

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

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

	} InputReader public BufferedReader reader; reader public StringTokenizer tokenizer; tokenizer public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		} InputReader {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		} reader = new BufferedReader(new InputStreamReader(stream), 32768) reader new BufferedReader(new InputStreamReader(stream), 32768) tokenizer = null tokenizer null InputStream stream stream public String next() {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
			return tokenizer.nextToken();
		} next {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
			return tokenizer.nextToken();
		} while (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 int nextInt() {
			return Integer.parseInt(next());
		} nextInt {
			return Integer.parseInt(next());
		} return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		Task solver = new Task();
		solver.solve(1, in, out);
		out.close();
	}

	static class Task {
		public void solve(int testNumber, InputReader 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) {
	            System.out.println("YES");
	        }else{
	            System.out.println("NO");
			}
		}
	}
	
	static class InputReader {
		public BufferedReader reader;
		public StringTokenizer tokenizer;

		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}

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

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

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

	static class Task {
		public void solve(int testNumber, InputReader 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) {
	            System.out.println("YES");
	        }else{
	            System.out.println("NO");
			}
		}
	}
	
	static class InputReader {
		public BufferedReader reader;
		public StringTokenizer tokenizer;

		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}

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

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

	}
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;

/**
 * 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;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		Task solver = new Task();
		solver.solve(1, in, out);
		out.close();
	}

	static class Task {
		public void solve(int testNumber, InputReader 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) {
	            System.out.println("YES");
	        }else{
	            System.out.println("NO");
			}
		}
	}
	
	static class InputReader {
		public BufferedReader reader;
		public StringTokenizer tokenizer;

		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}

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

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

	}
}
