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)

#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define E "\n"

using namespace std;
const long long MOD = (long long)1e9 + 7;

int n;
string s;

int main()
{
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> s;
    n = s.length();
    if (n % 2 == 0) {
        bool flag = true;
        for (int i = 0; i < n; i += 2) {
            if (s[i] != 'h' || s[i + 1] != 'i') {
                flag = false;
                break;
            }
        }
        if (flag) cout << "Yes" << E;
        else cout << "No" << E;
    }
    else cout << "No" << E;
    //system("pause");
    return 0;
}