diff --git a/Chapter03/binary_search.py b/Chapter03/binary_search.py
index d07b955..09a6444 100644
--- a/Chapter03/binary_search.py
+++ b/Chapter03/binary_search.py
@@ -1,6 +1,6 @@
 def binary_search(arr, start, end, key):
     while start <= end:  
-        mid = start + (end - start)/2)
+        mid = start + (end - start)//2
         if arr[mid] == key:  
             return mid  
         elif arr[mid] < key:  
diff --git a/README.md b/README.md
index 12ec142..94bd315 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,9 @@
+
+
+
 # Hands-On Data-Structures-and-Algorithms-with-Python-Third-Edition-published-by-Packt
 Hands-On Data Structures and Algorithms with Python – Third Edition
+### Download a free PDF
+
+ <i>If you have already purchased a print or Kindle version of this book, you can get a DRM-free PDF version at no cost.<br>Simply click on the link to claim your free PDF.</i>
+<p align="center"> <a href="https://packt.link/free-ebook/9781801073448">https://packt.link/free-ebook/9781801073448 </a> </p>
\ No newline at end of file
diff --git a/errata.md b/errata.md
new file mode 100644
index 0000000..9cc9cd7
--- /dev/null
+++ b/errata.md
@@ -0,0 +1,52 @@
+# Errata, Corrections and Improvements
+----------------------------------------------------
+If you find any mistakes in the third edition of Hands On Data Structures and Algorithms with Python book, or if you have suggestions for improvements, then please [raise an issue in this repository]([https://github.com/PacktPublishing/JavaScript-from-Beginner-to-Professional/issues](https://github.com/PacktPublishing/Hands-On-Data-Structures-and-Algorithms-with-Python-Third-Edition/issues)), or email to us.
+
+## Chapter 13, Page 403 - Fixing the reference to `ord` array
+
+There should be a reference calling to the `ord` array as `ord_text` in the `generate_hash` function.
+
+Incorrect code is:
+```
+else:
+    hash_text[i] = ((hash_text[i-1] - ord_text[i-1]) + ord[i+len_pattern-1]) # calculating next hash value using previous value
+```
+Correct code is:
+```
+else:
+    hash_text[i] = ((hash_text[i-1] - ord_text[i-1]) + ord_text[i+len_pattern-1]) # calculating next hash value using previous value
+```
+
+## Chapter 3, Page 61 - Fixed the missing '/' in `binary search` code
+
+There should be `//` in place of `/`
+
+Incorrect code is:
+```python
+mid = start + (end - start)/2
+if arr[mid] == key:  
+   return mid
+```
+Correct code is:
+```python
+mid = start + (end - start)//2
+if arr[mid] == key:  
+   return mid
+```
+
+
+## Chapter 1, Page 23 - Fixed the missing outputs
+
+This is the actual dictionary
+`mydict = {'a': 1, 'b': 2, 'c': 3}`
+
+|Function |Description |Example|
+| :-------:|  :-------: | :-------: | 
+| `mydict.pop()`| If a given key is present in the dictionary, then this function will remove the key and return the associated value.   | `print(mydict.pop('b'))` should give you output `2` |
+|              `|    | `print(mydict)` should give you output `{'a': 1, 'c': 3}` |
+| `mydict.popitem()`|  This method removes the last key-value pair added in the dictionary and returns it as a tuple.  | `print(mydict.popitem())` should give you output `('c', 3)` |
+|              `|    | `print(mydict)` should give you output `{'a': 1, 'b': 2}` |
+| `mydict.update(<obj>)`| Merges one dictionary with another. Firstly, it checks whether a key of the second dictionary is present in the fi rst dictionary; the corresponding value is then updated. If the key is not present in the fi rst dictionary, then the key-value pair is added.   | It has two dictionaries as `d1 = {'a': 10, 'b': 20, 'c': 30}` and `d2 = {'b': 200, 'd': 400}`|
+|                       |    | `d1.update(d2)` should update values of `d2` on `d1` |
+|                       |    | `print(d1)` should give you `{'a': 10, 'b': 200, 'c': 30, 'd': 400}` |
+