#include <bits/stdc++.h>
using namespace std;
int main() {
  long long i = 0;
  long long a = 0, b = 0, c = 0, d = 0, e = 0, m = 0;
  char s[150];
  gets(s);
  long long n = strlen(s);
  for (i = 0; i < n; i++) {
    if (s[i] == 'h')
      a++;
    else if (s[i] == 'e' && a >= 1)
      b++;
    else if (s[i] == 'l' && b >= 1)
      c++;
    else if (s[i] == 'o' && c >= 2)
      e++;
    else
      m;
  }
  if (a >= 1 && b >= 1 && c >= 1 && e >= 1)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
  return 0;
}
