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

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

int main() {
    string S;
    cin >> S;
    int cur = 0;
    while (cur < S.size()) {
        if (cur + 1 < S.size() && S[cur] == 'h' && S[cur + 1] == 'i') {
            cur += 2;
        } else {
            break;
        }
    }
    if (cur < S.size()) {
        cout << "No" << endl;
    } else {
        cout << "Yes" << endl;
    }
    return 0;
}