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;
#define pb push_back
#define all(v) v.begin(),v.end()
#define mem(arr) memset(arr,0,sizeof(arr))
#define ff first
#define ss second
#define int long long int
const int MOD = 1e9 + 7;
const int INF = 1e18;
const int N = 1e6 + 20;
vector<int> g[N];
vector<int> vis(N);
int32_t  main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int tc = 1;
    while(tc--){
        string s;
        cin >> s;
        int flag = 0;
        for(int i = 0; i < (int)s.length(); i += 2){
            if(!(s[i] == 'h' and s[i + 1] == 'i')){
                flag = 1;
                break;
            }
        }
        if(flag){
            cout << "No\n";
        }else{
            cout << "Yes\n";
        }
    } 
}