As it's the first of April, Heidi is suspecting that the news she reads today are fake, and she does not want to look silly in front of all the contestants. She knows that a newspiece is fake if it contains heidi as a subsequence. Help Heidi assess whether the given piece is true, but please be discreet about it...

Input

The first and only line of input contains a single nonempty string s of length at most 1000 composed of lowercase letters (a-z).

Output

Output YES if the string s contains heidi as a subsequence and NO otherwise.

见题面 Input 部分

见题面 Output 部分

A string s contains another string p as a subsequence if it is possible to delete some characters from s and obtain p.