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 INF INT_MAX
#define UINF UINT_MAX
#define MOD 1000000007
#define REP(i,n) for(int i=0;i<n;i++)
#define all(x) (x).begin(),(x).end()

typedef long long ll;
typedef std::pair<int,int> pii;

using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    string n; 
    cin >> n;

    string ans = "Yes";
    if(n.size() % 2 != 0){
        cout << "No" << endl;
        return 0;
    }
    for(int i = 0;i < n.size();i+=2){
        if(n[i] == 'h' && n[i+1] == 'i')continue;
        else{
            ans = "No";
            break;
        }
    }

    cout << ans << endl;
    return 0;
}