#include<iostream>
using namespace std;
int main()
{
	char s[20];
	cin>>s;
	int i,r=0;
	for(i=0;s[i]!='\0';i=i+2)
	{
		if(s[i]!='h'||s[i+1]!='i')
		
		r=1;
	}
	if(r==0)
	cout<<"Yes";
	else
	cout<<"No";
}