#include<bits/stdc++.h>
using namespace std;
int main(){int i,n,k=0;
string s;
cin>>s;n=s.size();
if(n%2){k=1;}
n/=2;
for(i=0;i<n;i++){if(s[2*i]!='h'||s[2*i+1]!='i'){k++;}}
if(k){cout<<"No";}
else{cout<<"Yes";}
    return 0;}