using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;

class Myon
{
    public Myon() { }
    public static int Main()
    {
        cin = new Scanner();
        new Myon().calc();
        return 0;
    }

    static Scanner cin;

    // メンバ変数---
    char[] S;
    // -------------

    void calc()
    {
        S = cin.next().ToCharArray();
        Array.Reverse(S);
        char[] tmparray;
        tmparray = "dream".ToCharArray();
        Array.Reverse(tmparray);
        string dream = new string(tmparray);
        tmparray = "dreamer".ToCharArray();
        Array.Reverse(tmparray);
        string dreamer = new string(tmparray);
        tmparray = "erase".ToCharArray();
        Array.Reverse(tmparray);
        string erase = new string(tmparray);
        tmparray = "eraser".ToCharArray();
        Array.Reverse(tmparray);
        string eraser = new string(tmparray);

        HashSet<string> dreamarray = new HashSet<string> { dream, dreamer, erase, eraser };

        string tmp = string.Empty;
        for (int i = 0; i < S.Length; i++)
        {
            tmp += S[i].ToString();
            if (dreamarray.Contains(tmp))
            {
                tmp = string.Empty;
            }
            if(tmp.Length > 7)
            {
                break;
            }
        }

        if (string.IsNullOrEmpty(tmp))
        {
            Write<string>("YES");
        }
        else
        {
            Write<string>("NO");
        }

    }

    void Write<T>(T v)
    {
        Console.WriteLine(v);
    }

    int Pow(int x, int y)
    {
        return (int)Math.Pow(double.Parse(x.ToString()), double.Parse(y.ToString()));
    }

    double Pow(double x, double y)
    {
        return Math.Pow(x, y);
    }

    class Scanner
    {
        string[] s;
        int i;

        char[] cs = new char[] { ' ' };

        public Scanner()
        {
            s = new string[0];
            i = 0;
        }

        public string next()
        {
            if (i < s.Length) return s[i++];
            string st = Console.ReadLine();
            while (st == "") st = Console.ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            if (s.Length == 0) return next();
            i = 0;
            return s[i++];
        }

        public int nextInt()
        {
            return int.Parse(next());
        }
        public int[] ArrayInt(int N, int add = 0)
        {
            int[] Array = new int[N];
            for (int i = 0; i < N; i++)
            {
                Array[i] = nextInt() + add;
            }
            return Array;
        }

        public long nextLong()
        {
            return long.Parse(next());
        }

        public long[] ArrayLong(int N, long add = 0)
        {
            long[] Array = new long[N];
            for (int i = 0; i < N; i++)
            {
                Array[i] = nextLong() + add;
            }
            return Array;
        }

        public double nextDouble()
        {
            return double.Parse(next());
        }


        public double[] ArrayDouble(int N, double add = 0)
        {
            double[] Array = new double[N];
            for (int i = 0; i < N; i++)
            {
                Array[i] = nextDouble() + add;
            }
            return Array;
        }
    }
}


Measured memory_bytes: 18512