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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <vector>
#include <cstring>
#include <cmath>
#include <string>
#include <map>
#include <set>
#include <iostream>

typedef long long ll;

using namespace std;

int main() {
	string s;
	cin >> s;
	while (s.size() >= 2 && s.back() == 'i' && s[s.size() - 2] == 'h') {
		s.pop_back();
		s.pop_back();
	}
	if (s.size() == 0) {
		puts("Yes");
	}
	else {
		puts("No");
	}
	return 0;
}