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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;

int main() {
    string s;
    cin >> s;
    if (s.length()%2 != 0) {
        cout << "No" << endl;
        return 0;
    }
    else {
        for (int i = 0; i < s.length(); i++) {
            if (i%2==0 && s[i]!='h' || i%2==1 && s[i]!='i') {
                cout << "No" << endl;
                return 0;
            }
        }
    }

    cout << "Yes" << endl;
}