#include <iostream>
#include <cstdio>

using namespace std;

string s;

int main()
{
    cin>>s;
    if(s == "hi" || s == "hihi" || s == "hihihi" || s == "hihihihi" || s == "hihihihihi") cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
    return 0;
}
