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: Runtime Error)

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

	    Scanner sc = new Scanner(System.in);
	    String S = sc.next();
	    char[] s = S.toCharArray();

	    boolean flg = false;
	    for (int i = 0; i < s.length; i++) {
	    	if (s[i] == 'h' && s[i+1] == 'i' && s[i+2] != 'i') {
	    		flg = true;
	    		break;
	    	}
	    }

	    if (flg) {
	    	System.out.println("Yes");
	    } else {
	    	System.out.println("No");
	    }
	}

}