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


int main()
 {
	string s;
	cin>>s;

	for(int i=0;i<s.length();i+=2)
	{
		if(s[i]=='h'&&s[i+1]=='i')
		{

		}
		else
			{
				cout<<"No"<<endl;
				return 0;
			}
	}
	cout<<"Yes"<<endl;
	return 0;
}