#include<iostream>
#include<string>

using namespace std;

int main(){

    string s; cin >> s;

    if(s=="hi" || s== "hihi" || s=="hihihi" || s=="hihihihi" || s=="hihihihihi"){
        cout << "Yes" << endl;
    }else{
        cout << "No" << endl;
    }
    
}