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>
#define REP(i, n) for (int i = 0; i < (n); i++)
using namespace std;

int main() {
    cin.tie(0)->sync_with_stdio(false);

    string s;
    cin >> s;
    int n = s.size();

    bool ok = true;
    if (n % 2) ok = false;
    else {
        REP(i, n) {
            if (i % 2) {
                if (s[i] != 'i')
                    ok = false;
            } else {
                if (s[i] != 'h')
                    ok = false;
            }
        }
    }

    if (ok) cout << "Yes" << '\n';
    else cout << "No" << '\n';
    return 0;
}