#include <bits/stdc++.h>
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;
  }
}
