diff --git a/DataScience/Assignments/HW4.pdf b/DataScience/Assignments/HW4.pdf
deleted file mode 100644
index be3ca60..0000000
Binary files a/DataScience/Assignments/HW4.pdf and /dev/null differ
diff --git a/DataScience/Assignments/HW5.pdf b/DataScience/Assignments/HW5.pdf
deleted file mode 100644
index e000c88..0000000
Binary files a/DataScience/Assignments/HW5.pdf and /dev/null differ
diff --git a/DataScience/Assignments/HW6.pdf b/DataScience/Assignments/HW6.pdf
deleted file mode 100644
index b59e2cc..0000000
Binary files a/DataScience/Assignments/HW6.pdf and /dev/null differ
diff --git a/DataScience/Assignments/HW7.pdf b/DataScience/Assignments/HW7.pdf
deleted file mode 100644
index e0f34c1..0000000
Binary files a/DataScience/Assignments/HW7.pdf and /dev/null differ
diff --git a/DataScience/Assignments/HW8.pdf b/DataScience/Assignments/HW8.pdf
deleted file mode 100644
index 6887de5..0000000
Binary files a/DataScience/Assignments/HW8.pdf and /dev/null differ
diff --git a/DataScience/Assignments/HW9.pdf b/DataScience/Assignments/HW9.pdf
deleted file mode 100644
index 81529f2..0000000
Binary files a/DataScience/Assignments/HW9.pdf and /dev/null differ
diff --git a/DataScience/Assignments/OP01.pdf b/DataScience/Assignments/OP01.pdf
new file mode 100644
index 0000000..940d012
Binary files /dev/null and b/DataScience/Assignments/OP01.pdf differ
diff --git a/DataScience/Assignments/Prob1.pdf b/DataScience/Assignments/PR01.pdf
similarity index 100%
rename from DataScience/Assignments/Prob1.pdf
rename to DataScience/Assignments/PR01.pdf
diff --git a/DataScience/Assignments/Prob3.pdf b/DataScience/Assignments/PR02.pdf
similarity index 100%
rename from DataScience/Assignments/Prob3.pdf
rename to DataScience/Assignments/PR02.pdf
diff --git a/DataScience/Assignments/HW2.pdf b/DataScience/Assignments/PR03.pdf
similarity index 100%
rename from DataScience/Assignments/HW2.pdf
rename to DataScience/Assignments/PR03.pdf
diff --git a/DataScience/README.md b/DataScience/README.md
index 16b0eff..82f164f 100644
--- a/DataScience/README.md
+++ b/DataScience/README.md
@@ -22,26 +22,28 @@
     *   Chapter 4: 6, 7, 12, 14, 31.
     *   Chapter 6: 3
     *   Chapter 7: 1
-    *   [HW1](Assignments/Prob1.pdf), [HW2](Assignments/Prob3.pdf), and [HW3](Assignments/HW2.pdf)
+    *   Probability HWs from [here](Assignments)
 2.  Review the basics of Data Visualization
 
 *   [Visualization Code](Code/Code-By-TAs)
 
 4.  Review the basics of Linear Algebra
-    *   Chapter 1:  
-        Sec 1.1: 1 , 2, 4, 7, 13.  
+    *   Chapter 1:
+        Sec 1.1: 1 , 2, 4, 7, 13.
         Sec 1.2: 1,3,4.
-    *   Chapter 4:  
+    *   Chapter 4:
         Sec 4.2: 1,11.
 5.  Review the basics of Multivariate Probability and Statistics
     *   [Multivariate Example](Code/Code-By-TAs)
 
+6. Review some basics of Calculus and solve optimization problems from [here](Assignments).
+
 ## Suggested Projects
 
-coming soon  
+coming soon
 
 ## **Announcements**
 
-Please, find here [samples for exams.](Exams)  
+Please, find here [samples for exams.](Exams)
 
 * * *
diff --git a/PatternRecognition/LectureNotes/Shots/white.png b/PatternRecognition/LectureNotes/Shots/white.png
index 768c70f..a6b9af8 100644
Binary files a/PatternRecognition/LectureNotes/Shots/white.png and b/PatternRecognition/LectureNotes/Shots/white.png differ