Vasya has recently learned to type and log on to the Internet. He immediately entered a chat room and decided to say hello to everybody. Vasya typed the word *s*. It is considered that Vasya managed to say hello if several letters can be deleted from the typed word so that it resulted in the word "hello". For example, if Vasya types the word "ahhellllloou", it will be considered that he said hello, and if he types "hlelo", it will be considered that Vasya got misunderstood and he didn't manage to say hello. Determine whether Vasya managed to say hello by the given word *s*.
The first and only line contains the word *s*, which Vasya typed. This word consisits of small Latin letters, its length is no less that 1 and no more than 100 letters.
'''
Chat room - Codeforces
https://codeforces.com/problemset/problem/58/A

Problem Details:
    word_base = "hello"

    example:
        input: hlelo
        la primera letra de input es h?
            si
                la siguiente letra es e?
                    si
                    no
                        la siguienta letra es h?
                        si
                            busca e

# rules:
    - if count size of input string is less than 5 print NO
    - if we found the "hello" stop traversing the input and print YES
    - if curr_char_input is equal to char_to_find
        - yes, update char_to_find to next_char_from_word_base, check next_char_input
        - no
            - check curr_char_input is repeated, or first char (same as last one)
            - check next_char_input<<<----

test:
input = 'helll'
             ^
curr_char_input = l
char_to_find = o <---- no more chars to find, return YES, break
j = 4
last_char_found = 'l' <--- if curr_char_input != last_char_found break, return NO
'''
def word_typed (string):
    word_base = 'hello'
    j = 0
    n = len(string)
    char_to_find = word_base[j]
    last_char_found = ''
    for i in range(n):
        curr_char_input = string[i]
        if curr_char_input == char_to_find:
            j += 1
            if j == 5:
                return 'YES'
            last_char_found = char_to_find
            char_to_find = word_base[j]
        elif last_char_found != '' and curr_char_input != last_char_found:
            return 'NO'
    return 'NO'

s = input()
print(word_typed(s))

