#include <bits/stdc++.h>
using namespace std;
int main() {
  string a;
  cin >> a;
  int count = 0, pin = 0;
  int b = a.length();
  for (int i = 0; i < b; i++) {
    if (count == 0 && int(a[i]) == 104) {
      count += 1;
    } else if (count == 1 && int(a[i]) == 101) {
      count += 1;
    } else if (count == 2 && int(a[i]) == 108) {
      count += 1;
    } else if (count == 3 && int(a[i]) == 108) {
      count += 1;
    } else if (count == 4 && int(a[i]) == 111) {
      count += 1;
    } else {
      pin += 1;
    }
  }
  if (count == 5) {
    cout << "YES";
  } else {
    cout << "NO";
  }
  return 0;
}
