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

int main() {
  string S, Sc = "";
  cin >> S;
  for (int i = 0; i < S.size()/2; i++) {
    Sc += "hi";
  }
  if (S == Sc) cout << "Yes" << endl;
  else cout << "No" << endl;
}