#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";
  } else {
    cout << "No";
  }
  
}
