#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef vector<char> VC;
typedef vector<double> VD;
typedef vector<string> VS;
typedef vector<ll> VLL;
typedef vector<PLL> VP;
const static int INF = 1000000000;
const static int MOD = 1000000007;
#define rep(i,n) for (ll i=0; i<(ll)(n); i++)
#define repd(i,n) for (ll i=n-1; i>=0; i--)
#define rept(i,m,n) for(ll i=m; i<n; i++)
#define stl_rep(itr, x) for (auto itr = x.begin(); itr != x.end(); ++itr)
#define all(x) (x).begin(), (x).end()
#define F first
#define S second
#define PF push_front
#define PB push_back
#define SORT(V) sort((V).begin(), (V).end())
#define RVERSE(V) reverse((V).begin(), (V).end())
#define paired make_pair
#define PRINT(V) for(auto v : (V)) cout << v << " "
//charを整数に
int ctoi(char c) { if (c >= '0' && c <= '9') { return c - '0'; } return 0; }
// 累積和 for (int i = 0; i < N; ++i) s[i+1] = s[i] + a[i]; 
void cum_sum(int N,vector<double> a, vector<double> &s){ for(int i=0; i<N; i++){ s[i+1]=s[i]+a[i];}}
//ユークリッドの控除法
ll gcd(ll a,ll b){
    if(b == 0) return a;
    return gcd(b,a%b);
}
//最小公倍数
ll lcm(ll a,ll b){
    ll g = gcd(a,b);
    return a / g * b; // Be careful not to overflow
}
//素数判定
bool is_prime(long long n) {
    if (n <= 1) return false;
    for (long long p = 2; p * p <= n; ++p) {
        if (n % p == 0) return false;
    }
    return true;
}
int getdigit(ll num){
    unsigned digit=0;
    while(num!=0){
        num /= 10;
        digit++;
    }
    return digit;
}
//空白文字も入力 getline(cin, S);
//桁数指定 setprecision

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    string S;
    cin >> S;
    if(S.size()<8){
        cout << "NO" << endl;
        return 0;
    }
    reverse(all(S));
    int counter=0;
    string tmp;
    while(1){
        if(counter==S.size()){
            break;
        }
        tmp.PB(S[counter]);
        if(tmp.size()==5){
            if(tmp=="maerd"){
                tmp.clear();
                if(S.size()-(counter+1)<5 && S.size()-(counter+1)!=0){
                    cout << "NO" << endl;
                    return 0;
                }
                counter++;
                continue;
            }
            else{
                if(tmp!="esare" && tmp!="resar" && tmp!="remae"){
                    cout << "NO" << endl;
                    return 0;
                }
            }
            if(tmp=="esare"){
                tmp.clear();
                if(S.size()-(counter+1)<5 && S.size()-(counter+1)!=0){
                    cout << "NO" << endl;
                    return 0;
                }
                counter++;
                continue;
            }
            else{
                if(tmp!="resar" && tmp!="remae" && tmp!="maerd"){
                    cout << "NO" << endl;
                    return 0;
                }
            }
        }
        if(tmp.size()==7){
            if(tmp=="remaerd"){
                tmp.clear();
                if(S.size()-(counter+1)<5 && S.size()-(counter+1)!=0){
                    cout << "NO" << endl;
                    return 0;
                }
                counter++;
                continue;
            }
            else{
                cout << "NO" << endl;
                return 0;
            }
        }
        if(tmp.size()==6){
            if(tmp=="resare"){
                tmp.clear();
                if(S.size()-(counter+1)<5 && S.size()-(counter+1)!=0){
                    cout << "NO" << endl;
                    return 0;
                }
                counter++;
                continue;
            }
            else{
                if(tmp!="remaer"){
                    cout << "NO" << endl;
                    return 0;
                }
            }
        }
        counter++;
    }
    cout << "YES" << endl;
}


Measured memory_bytes: 512