Chat room
该比赛已结束，您无法在比赛模式下递交该题目。您可以点击“在题库中打开”以普通模式查看和递交本题。
描述
Vasya最近学会了打字和上网。他立即进入了一个聊天室，并决定向大家打个招呼。Vasya输入了单词s。如果从输入的单词中删除几个字母后得到单词"hello"，则认为Vasya成功打招呼。例如，如果Vasya输入单词"ahhellllloou"，则认为他打招呼了，而如果他输入单词"hlelo"，则认为Vasya被误解了，他没有成功打招呼。确定Vasya是否成功打招呼，根据给定的单词s来判断。
输入
第一行有且仅有一个单词s，表示Vasya输入的单词。该单词由小写拉丁字母组成，长度不少于1个字母，不超过100个字母。
输出
如果Vasya成功打招呼，输出"YES"，否则输出"NO"。
输入
第一行有且仅有一个单词s，表示Vasya输入的单词。该单词由小写拉丁字母组成，长度不少于1个字母，不超过100个字母。
输出
如果Vasya成功打招呼，输出"YES"，否则输出"NO"。
样例
ahhellllloou
YES
hlelo
NO
Description
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.
If Vasya managed to say hello, print "YES", otherwise print "NO".
Input
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.
Output
If Vasya managed to say hello, print "YES", otherwise print "NO".
Samples
ahhellllloou
YES
hlelo
NO