import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.NoSuchElementException;

public class Main{
	static FastScanner sc = new FastScanner();
	static PrintWriter out = new PrintWriter(System.out);
	static String S;
	//static long n;
	
	public static void main(String[] args) {
		S = sc.next();
		int k = S.length();
		
		boolean flag = false;
		
		for (int i=k-1; i>=0; i--){
			if (S.charAt(i)=='e')
				i = e(S, i);
			
			else if (S.charAt(i)=='m')
				i = m(S, i);
			
			else if (S.charAt(i)=='r')
				i = r(S, i);
			
			else 
				i = -2;
			
			if (i==-2) {
				flag = true;
				break;
			}
		}
		
		if (flag)
			out.println("NO");
		
		else
			out.println("YES");
	
			
		out.flush();
	}
	
	static int e (String s, int j) {
		if (j-4<0)
			return -2;
		
		if (s.charAt(j)=='e' && s.charAt(j-1)=='s' && s.charAt(j-2)=='a' && s.charAt(j-3)=='r' && s.charAt(j-4)=='e')
			return j-4;
		
		else
			return -2;
	}
	
	static int r (String s, int j) {
		if (j-2<0)
			return -2;
		
		if (s.charAt(j)=='r' && s.charAt(j-1)=='e' && s.charAt(j-2)=='s')
			return j;
		
		else if (s.charAt(j)=='r' && s.charAt(j-1)=='e' && s.charAt(j-2)=='m')
			return j-1;
		
		else
			return -2;
	}
	
	static int m (String s, int j) {
		if (j-4<0)
			return -2;
		
		if (s.charAt(j)=='m' && s.charAt(j-1)=='a' && s.charAt(j-2)=='e' && s.charAt(j-3)=='r' && s.charAt(j-4)=='d')
			return j-4;
		
		else
			return -2;
	}

		static class FastScanner {
		    private final InputStream in = System.in;
		    private final byte[] buffer = new byte[1024];
		    private int ptr = 0;
		    private int buflen = 0;

		    private boolean hasNextByte() {
		      if (ptr < buflen) {
		        return true;
		      } else {
		        ptr = 0;
		        try {
		          buflen = in.read(buffer);
		        } catch (IOException e) {
		          e.printStackTrace();
		        }
		        if (buflen <= 0) {
		          return false;
		        }
		      }
		      return true;
		    }

		    private int readByte() {
		      if (hasNextByte()) return buffer[ptr++];
		      else return -1;
		    }

		    private static boolean isPrintableChar(int c) {
		      return 33 <= c && c <= 126;
		    }

		    private void skipUnprintable() {
		      while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
		    }

		    public boolean hasNext() {
		      skipUnprintable();
		      return hasNextByte();
		    }

		    public String next() {
		      if (!hasNext()) throw new NoSuchElementException();
		      StringBuilder sb = new StringBuilder();
		      int b = readByte();
		      while (isPrintableChar(b)) {
		        sb.appendCodePoint(b);
		        b = readByte();
		      }
		      return sb.toString();
		    }

		    public long nextLong() {
		      if (!hasNext()) throw new NoSuchElementException();
		      long n = 0;
		      boolean minus = false;
		      int b = readByte();
		      if (b == '-') {
		        minus = true;
		        b = readByte();
		      }
		      if (b < '0' || '9' < b) {
		        throw new NumberFormatException();
		      }
		      while (true) {
		        if ('0' <= b && b <= '9') {
		          n *= 10;
		          n += b - '0';
		        } else if (b == -1 || !isPrintableChar(b)) {
		          return minus ? -n : n;
		        } else {
		          throw new NumberFormatException();
		        }
		        b = readByte();
		      }
		    }

		    public int nextInt() {
		      return (int) nextLong();
		    }

		    public int[] nextIntArray(int N, boolean oneBased) {
		      if (oneBased) {
		        int[] array = new int[N + 1];
		        for (int i = 1; i <= N; i++) {
		          array[i] = sc.nextInt();
		        }
		        return array;
		      } else {
		        int[] array = new int[N];
		        for (int i = 0; i < N; i++) {
		          array[i] = sc.nextInt();
		        }
		        return array;
		      }
		    }

		    public long[] nextLongArray(int N, boolean oneBased) {
		      if (oneBased) {
		        long[] array = new long[N + 1];
		        for (int i = 1; i <= N; i++) {
		          array[i] = sc.nextLong();
		        }
		        return array;
		      } else {
		        long[] array = new long[N];
		        for (int i = 0; i < N; i++) {
		          array[i] = sc.nextLong();
		        }
		        return array;
		      }
		    }
		  }

		}	 





Measured memory_bytes: 21588