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: Accepted)

import java.util.Scanner;

class A {
    public static void main(String... args) {
        final Scanner sc = new Scanner(System.in);
        final char[] S = sc.next().toCharArray();
        boolean success = S.length % 2 == 0;
        for (int i = 0; i < S.length && success; i += 2)
            success = (S[i] == 'h' && S[i + 1] == 'i');
        System.out.println(success ? "Yes" : "No");
    }
}
public class Main {
    public static void main(String... args) {
        A.main();
    }
}