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 <iostream>

using namespace std;

int main() {
    string S;
    cin >> S;
    string out = "Yes";
    if(S.length() < 2){
        out = "No";
    }else{
        for(int i = 0; i < S.length(); i++){
            if(i % 2 == 0){
                if(S[i] != 'h'){
                    out = "No";
                    break;
                }
            }else{
                if(S[i] != 'i'){
                    out = "No";
                    break;
                }
            }
        }
    }
    cout << out << endl;
}