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

int main() {
  string s; cin>>s;
  for(int i=0; i<s.size(); i++){
    if(i%2==0 && (s[i]!='h' || s[i+1]!='i')){
      cout<<"No";
      return 0;
    }
  }
  cout<<"Yes";
}