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/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
//package Vidu;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.util.Scanner;

/**
 *
 * @author dinhd
 */
class HELLO {

    static int check(String b, char c) {
        int count = 0;
        for (int i = 0; i < b.length(); i++) {
            if (b.charAt(i) == c) {
                count++;
            }
        }
        return count;
    }

    public static void main(String[] args) throws IOException {
        if (!"true".equals(System.getProperty("ONLINE_JUDGE"))) {
            System.setIn(new FileInputStream(new File("input.txt")));
            System.setOut(new PrintStream(new File("output.txt")));
        }
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        sc.close();
        if (s.length() < 100) {
            char[] chararr = new char[s.length()];
            for (int i = 0; i < s.length(); i++) {
                chararr[i] = s.charAt(i);
            }
            String he = "";

            for (int i = chararr.length - 1; i >= 0; i--) {

                if (String.valueOf(chararr[i]).equalsIgnoreCase("o") && check(he, chararr[i]) < 1) {
                    he += "o";
                }
                if (String.valueOf(chararr[i]).equalsIgnoreCase("l") && check(he, chararr[i]) < 2 && (String.valueOf(he.charAt(he.length() - 1)).equalsIgnoreCase("o") || String.valueOf(he.charAt(he.length() - 1)).equalsIgnoreCase("l"))) {
                    he += "l";
                }
                if (String.valueOf(chararr[i]).equalsIgnoreCase("e") && check(he, chararr[i]) < 1 && String.valueOf(he.charAt(he.length() - 1)).equalsIgnoreCase("l")) {
                    he += "e";
                }
                if (String.valueOf(chararr[i]).equalsIgnoreCase("h") && check(he, chararr[i]) < 1 && String.valueOf(he.charAt(he.length() - 1)).equalsIgnoreCase("e")) {
                    he += "h";
                }

            }

            if (he.equalsIgnoreCase("olleh")) {
                System.out.print("YES");
            } else {
                System.out.println("NO");
            }

        }
    }

}