#include <bits/stdc++.h>
int main(){
  std::string s;
  std::cin >> s;
  if(s == "hi" || s == "hihi" || s == "hihihi" || s == "hihihihi" || s == "hihihihihi")
    std::cout << "Yes\n";
  else std::cout << "No\n";
}
