#include <bits/stdc++.h>
using namespace std;
int main(){
  string s;
  cin>>s;
  vector<string> a;
  string hoge="hi";
  a.push_back(hoge);
  for(int i=0;i<4;i++){
    hoge=hoge+"hi";
    a.push_back(hoge);
  }
  for(int i=0;i<5;i++){
    if(a[i]==s){
      cout<<"Yes"<<endl;
      return 0;
    }
  }
  cout<<"No"<<endl;
  return 0;
}

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

char S[15];

int main(){
    scanf(" %s", S);

    int len = strlen(S);
    if(len%2 != 0){
        printf("No");
        return 0;
    }
    for(int i = 0; i < len; i ++){
        if(i%2 == 0 && S[i] != 'h'){
            printf("No");
            return 0;
        }
        if(i%2 == 1 && S[i] != 'i'){
            printf("No");
            return 0;
        }
    }

    printf("Yes");
    return 0;
}
