#include <bits/stdc++.h>
using namespace std;

int main() {
  string str;
  cin >> str;
  if(str == "hi" || str == "hihi" || str == "hihihi" || str == "hihihihi" || str == "hihihihihi"){
    cout << "Yes";
  }
  else{
    cout << "No";
  }
}