#include<bits/stdc++.h>
using namespace std;
#define int long
using pi=pair<int,int>;
signed main(){
    string s,t="hi";
    cin>>s;
    for(int i=0;i<5;++i){
        if(t==s)return cout<<"Yes",0;
        t += "hi";
    }
    cout << "No";
}