Problem 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.
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".
Examples
Input
ahhellllloou
Output
YES
Input
hlelo
Output
NO
解题思路：题目很简单，就是从给定字符串中从头到尾依次查找是否有"hello"这个单词的每个字符（必须按顺序排列），如果有即为"YES"，否则为"NO"，简单AC。
AC代码：
1 #include<bits/stdc++.h> 2 using namespace std; 3 int main(){ 4 char obj[]="hello",s[105]; 5 int k=0; 6 cin>>s; 7 for(int i=0;s[i]!=' ';++i) 8 if(obj[k]==s[i])k++; 9 if(k!=5)cout<<"NO"<<endl; 10 else cout<<"YES"<<endl; 11 return 0; 12 }