#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll INF = 100100100100100;
int main() {
  string s;
  cin >> s;
  ll size = s.size();
  bool yes = true;
  if (size % 2 == 1)
    yes = false;
  else {
    for (int i = 0; i < size / 2; i++) {
      if (s[2 * i] == 'h' && s[2 * i + 1] == 'i')
        continue;
      else {
        yes = false;
        break;
      }
    }
  }
  if (yes)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
