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

int main() {
    string S; cin >> S;
    if(S == "hi" || S == "hihi" || S == "hihihi" || S == "hihihihi" || S == "hihihihihi") {
        cout << "Yes\n";
    } else {
        cout << "No\n";
    }
}