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>
using namespace std;
int main(void){
    
    string S;
    cin >> S;
    if(S.size()%2==1){
        cout << "No" << endl;
        return 0;
    }
    int H=0;
    for(int i=0; i<S.size(); i=i+2){
        if(S[i]=='h') H++;
    }
    int I=0;
    if(S.size()/2==H){
        for(int i=1; i<S.size(); i=i+2){
            if(S[i]=='i') I++;
        }
        if(S.size()/2==I) cout << "Yes" << endl;
        else cout << "No" << endl;
    }
    return 0;
    
}