using System;

using System.Text;                  

public class Program

{

    public static string hackerrankInString(string s) {

        StringBuilder copy = new StringBuilder();

        string target = "hackerrank";

​

        int i = 0;

        int j = 0;

        while(i < target.Length && j < s.Length)

        {   

            Console.WriteLine("index target: " + i + "  " + target[i]+ "  index string: " + j + "  " + s[j]);

            if(target[i] == s[j])

            {

                copy.Append(s[j]);

                i++;

                j++;                

            }

            else{

                j++;

            }

        }

        if(copy.ToString() == target)

            return "YES";

        else

        {

            return "NO";

        }

    } 

    public static void Main()

    {

        Console.WriteLine(hackerrankInString("haaacckserrannnnk"));

    }

}