#include <bits/stdc++.h>
using namespace std;
int i, n, m;
string s, v;
int main() {
  cin >> s;
  n = s.size();
  m = 0;
  v = "hello";
  for (i = 0; i < n; i++) {
    if (s[i] == v[m]) m++;
    if (m == 5) {
      cout << "YES";
      return 0;
    }
  }
  cout << "NO";
}
