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)

//#pragma Gbb optimize("Ofast") 
#include<set>
#include<map>
#include<cmath>
#include<queue>
#include<cstdio>
#include<string>
#include<vector>
#include<fstream>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<time.h>
#include<algorithm>
#define inf 0x3f3f3f3f
using namespace std;

string s;
char a[2] = { 'h','i' };

int main()
{
	cin >> s;
	int l = s.length();
	if (l % 2 == 0)
	{
		int j = 0;
		bool f = 1;
		for (int i = 0; i < l; i++)
			if (a[j] == s[i]) j = 1 - j;
			else
			{
				f = 0;
				break;
			}
		if (f) cout << "Yes";
		else cout << "No";
	}
	else cout << "No";
	return 0;
}