using System;
using System.Linq;
using System.Collections.Generic;

namespace Contest
{
    class Program
    {
        static void Main(string[] args)
        {
            ARC065.C();
        }
        class ARC065
        {
            public static void C()
            {
                var S = Read.Str();
                var strings = new string[] { "dream", "dreamer", "erase", "eraser" };
                int idx = S.Length - 1;
                while (idx >= 0)
                {
                    bool okAll = false;
                    foreach(var s in strings)
                    {
                        if (idx >= s.Length - 1)
                        {
                            bool ok = true;
                            for(int i = 0; i < s.Length; ++i)
                            {
                                if(s[i] != S[idx - s.Length + i + 1])
                                {
                                    ok = false; break;
                                }
                            }
                            if (ok)
                            {
                                okAll = true;
                                idx -= s.Length;
                                break;
                            }
                        }
                    }
                    if (!okAll) { Console.WriteLine("NO"); return; }
                }
                Console.WriteLine("YES");
            }
            public static void D()
            {
                var N = Read.Int();
                var K = Read.Int();
                var L = Read.Int();
                var PQ = Read.TupleInt(K);
                var RS = Read.TupleInt(L);
                var uft1 = new Util.UnionFindTree(N);
                var uft2 = new Util.UnionFindTree(N);
                foreach(var pq in PQ)
                {
                    uft1.Unite(pq.Item1 - 1, pq.Item2 - 1);
                }
                foreach(var rs in RS)
                {
                    uft2.Unite(rs.Item1 - 1, rs.Item2 - 1);
                }
                var dict1 = new Dictionary<int, HashSet<int>>();
                for(int i = 0; i < N; ++i)
                {
                    var r = uft1.Root(i);
                    if (!dict1.ContainsKey(r)) { dict1.Add(r, new HashSet<int>()); }
                    dict1[r].Add(i);
                }
                var ans = new int[N];
                foreach(var kvp1 in dict1)
                {
                    var dict2 = new Dictionary<int, HashSet<int>>();
                    foreach(var i in kvp1.Value)
                    {
                        var r = uft2.Root(i);
                        if (!dict2.ContainsKey(r)) { dict2.Add(r, new HashSet<int>()); }
                        dict2[r].Add(i);
                    }
                    foreach(var kvp2 in dict2)
                    {
                        foreach(var i in kvp2.Value)
                        {
                            ans[i] = kvp2.Value.Count;
                        }
                    }
                }
                Console.WriteLine(String.Join(" ", ans));
            }
        }
        class Util
        {
            public class UnionFindTree
            { //各Treeのサイズを保持する拡張仕様
                int[] parent;
                int[] count;
                public UnionFindTree(int n) { parent = new int[n]; count = new int[n]; for (int i = 0; i < n; ++i) { parent[i] = i; count[i] = 1; } }
                public int Root(int i) { if (parent[i] == i) { return i; } else { return parent[i] = Root(parent[i]); } }
                public int Count(int i) { return count[Root(i)]; }
                public bool Same(int i, int j) { return Root(i) == Root(j); }
                public void Unite(int i, int j) { var ri = Root(i); var rj = Root(j); if (ri != rj) { parent[ri] = rj; count[rj] += count[ri]; } }
            }
        }

        static class Read
        {
            static Queue<string> queue = new Queue<string>();
            static void Enqueue() { var ss = Console.ReadLine().Split(' '); foreach (var s in ss) { queue.Enqueue(s); } }
            public static int Int() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt32(queue.Dequeue()); }
            public static long Long() { if (queue.Count == 0) { Enqueue(); } return Convert.ToInt64(queue.Dequeue()); }
            public static string Str() { if (queue.Count == 0) { Enqueue(); } return queue.Dequeue(); }
            public static int[] IntN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt32(s)).ToArray(); }
            public static long[] LongN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToInt64(s)).ToArray(); }
            public static ulong[] ULongN() { return Console.ReadLine().Split(' ').Select(s => Convert.ToUInt64(s)).ToArray(); }
            public static string[] StrN() { return Console.ReadLine().Split(' '); }
            public static Tuple<int, int>[] TupleInt(int n) { List<Tuple<int, int>> list = new List<Tuple<int, int>>(); for (int i = 0; i < n; ++i) { var ab = Read.IntN(); list.Add(new Tuple<int, int>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<long, long>[] TupleLong(int n) { List<Tuple<long, long>> list = new List<Tuple<long, long>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<long, long>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<string, string>[] TupleStr(int n) { List<Tuple<string, string>> list = new List<Tuple<string, string>>(); for (int i = 0; i < n; ++i) { var ab = Read.StrN(); list.Add(new Tuple<string, string>(ab[0], ab[1])); } return list.ToArray(); }
            public static Tuple<double, double>[] TupleDouble(int n) { List<Tuple<double, double>> list = new List<Tuple<double, double>>(); for (int i = 0; i < n; ++i) { var ab = Read.LongN(); list.Add(new Tuple<double, double>(ab[0], ab[1])); } return list.ToArray(); }
            public static long[,] LongMatrix(int r, int c)
            {
                var mat = new long[r, c];
                for (int i = 0; i < r; ++i)
                {
                    var x = Read.LongN();
                    for (int j = 0; j < c; ++j)
                    {
                        mat[i, j] = x[j];
                    }
                }
                return mat;
            }
            public static Dictionary<int, HashSet<int>> AdjacencyList(int N, int M, bool isDirectional = false)
            {
                Dictionary<int, HashSet<int>> dict = new Dictionary<int, HashSet<int>>();
                for (int i = 0; i <= N; ++i) { dict.Add(i, new HashSet<int>()); }
                for (int i = 0; i < M; ++i)
                {
                    var ab = Read.IntN(); dict[ab[0]].Add(ab[1]);
                    if (!isDirectional) { dict[ab[1]].Add(ab[0]); }
                }
                return dict;
            }
            public static Dictionary<int, Dictionary<int, long>> AdjacencyListWithWeight(int N, int M)
            {
                Dictionary<int, Dictionary<int, long>> dict = new Dictionary<int, Dictionary<int, long>>();
                for (int i = 0; i <= N; ++i)
                {
                    dict.Add(i, new Dictionary<int, long>());
                }
                for (int i = 0; i < M; ++i)
                {
                    var ab = Read.IntN();
                    dict[ab[0]].Add(ab[1], ab[2]);
                    dict[ab[1]].Add(ab[0], ab[2]);
                }
                return dict;
            }
        }
    }
}


Measured memory_bytes: 11744