Problem:
Score : 100 points

Problem Statement

A Hitachi string is a concatenation of one or more copies of the string hi.

For example, hi and hihi are Hitachi strings, while ha and hii are not.

Given a string S, determine whether S is a Hitachi string.

Constraints

The length of S is between 1 and 10 (inclusive).

S is a string consisting of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If S is a Hitachi string, print Yes; otherwise, print No.

Sample Input 1

hihi

Sample Output 1

Yes

hihi is the concatenation of two copies of hi, so it is a Hitachi string.

Sample Input 2

hi

Sample Output 2

Yes

Sample Input 3

ha

Sample Output 3

No

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.io.*;
import java.util.*;

public class Main{
    public static void main(String[] args)throws Exception{
        Scanner sc=new Scanner(System.in);
        String s=sc.next();
        int l=s.length();
        boolean flag=true;
        char c=s.charAt(0);
        for(int i=1;i<l;i++){
            if(c=='h'){
                if(s.charAt(i)!='i')flag=false;
            }else if(c=='i'){
                if(s.charAt(i)!='h')flag=false;
            }else{
                flag=false;
            }
            c=s.charAt(i);
        }
        if(flag){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
    }
}