#include<iostream>
using namespace std;

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