#include <bits/stdc++.h>
using namespace std;
int main() {
  string str;
  cin >> str;
  string out = "";
  int ls = 0;
  if (str[0] == 'h') out += 'h';
  for (int i = 1; i < str.length(); i++) {
    if ((str[i] == 'h' && out.empty() ||
         out.size() &&
             (str[i] == 'e' && out[out.size() - 1] == 'h' ||
              str[i] == 'o' && out[out.size() - 1] == 'l' && ls >= 2) &&
             str[i] != str[i - 1]))
      out += str[i];
    else if (str[i] == 'l' &&
             (out[out.size() - 1] == 'e' || out[out.size() - 1] == 'l') &&
             ls < 2)
      ls++, out += str[i];
  }
  if (out == "hello")
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}
