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)

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

typedef long long ll;

// static const int MAX = 1e6;
// static const int NIL = -1;
// static const ll INF = 1<<21;
// static const ll MOD = 1e9 + 7;

bool compPair(const pair<int, int>& arg1, const pair<int, int>& arg2) {
    return arg1.first > arg2.first;
}

int main(void) {
    string s;
    cin >> s;

    if(s.size()%2==1) {
        cout << "No" << endl;
        return 0;
    }
    for(int i=0;i<s.size();i++) {
        if((i%2==0&&s.at(i)=='h')||(i%2==1&&s.at(i)=='i')) ;
        else {
            cout << "No" << endl;
            return 0;
        }
    }

    cout << "Yes" << endl;
    return 0;
}