#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[101];
  int c = 0;
  gets(s);
  int hello[4] = {0, 0, 0, 0};
  int len = strlen(s);
  int i, j, k, l, m;
  for (i = 0; i < len; i++) {
    if (s[i] == 'h') {
      c++;
      for (j = i; j < len; j++) {
        if (s[j] == 'e') {
          c++;
          for (k = j; k < len; k++) {
            if (s[k] == 'l') c++;
            if (c == 4) {
              for (m = k; m < len; m++) {
                if (s[m] == 'o') {
                  c++;
                  cout << "YES" << endl;
                  ;
                  return 0;
                  break;
                }
              }
              k = m;
            }
            if (c == 5) break;
          }
          j = k;
          if (c == 5) break;
        }
        if (c == 5) break;
      }
      i = k;
      if (c == 5) break;
    }
    if (c == 5) break;
  }
  cout << "NO" << endl;
  return 0;
}
