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.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		sc.close();

		if ( S.length() <= 1 ) {
			System.out.println("No");
			return;
		}
		
		String ans = "Yes";
		for ( int i = 0 ; i < S.length() ; i++ ) {
			if ( i % 2 == 0 ) {
				if ( S.charAt(i) != 'h' ) {
					ans = "No";
					break;
				}
			} else {
				if ( S.charAt(i) != 'i' ) {
					ans = "No";
					break;
				}
			}
		}
		System.out.println(ans);
	}
}