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: Wrong Answer)

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 1e5 + 10;
char ch[N];
signed main() {
	cin >> ch + 1;
	int fl = 1;
	if (strlen(ch + 1) % 2) {
		cout << "No " << endl;
		return 0;
	}

	for (int i = 1; i <= strlen(ch + 1); i++) {
		if (i % 2) {
			if (ch[i] != 'i') {
				fl = 0;
				break;
			}
		}
		else {
			if (ch[i] != 'h') {
				fl = 0;
				break;
			}
		}
	}
	if (fl) {
		cout << "Yes" << endl;
	}
	else {
		cout << "No" << endl;
	}
	return 0;
}