#include <bits/stdc++.h>
using namespace std;
int main() {
  string input;
  cin >> input;
  int n = input.size();
  bool verfied = false;
  bool _h = false;
  bool _e = false;
  bool _l1 = false;
  bool _l2 = false;
  bool _o = false;
  for (int i = 0; i < n; i++) {
    char letter = input[i];
    if (!_h && letter == 'h') {
      _h = true;
      continue;
    }
    if (_h && !_e && letter == 'e') {
      _e = true;
      continue;
    }
    if (_h && _e && !_l1 && letter == 'l') {
      _l1 = true;
      continue;
    }
    if (_h && _e && _l1 && !_l2 && letter == 'l') {
      _l2 = true;
      continue;
    }
    if (_h && _e && _l1 && _l2 && !_o && letter == 'o') {
      _o = true;
      verfied = true;
      break;
    }
  }
  if (verfied) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }
  return 0;
}
