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

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