import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
    
    public static void solve (String s){
        char[] charArray = s.toCharArray();

        int h=0,a=0,c=0,k=0,e=0,r=0,n=0;
        
        for (char character : charArray) {
            if(character == 'h'){
                h++;
            }
            if(character == 'a'){
                a++;
            }
            if(character == 'c'){
                c++;
            }
            if(character == 'k'){
                k++;
            }
            if(character == 'e'){
                e++;
            }
            if(character == 'r'){
                r++;
            }
            if(character == 'n'){
                n++;
            }
            
        }
        
        if(h >= 1 && a >= 2 && c >= 1 && k >= 2 && e >= 1 && r >= 2 && n >= 1){
            System.out.println("YES");
        }else{
            System.out.println("NO");
        }
         
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int q = in.nextInt();
        in.nextLine();
        solve(in.nextLine());
        solve(in.nextLine());
        
    }
}