This book contains material from "CS50’s Introduction to Computer Science" by Harvard University, available at https://learning.edx.org/course/course-v1:HarvardX+CS50+X/home, used under the Creative Commons Attribution 4.0 International License. Changes were made by Danobong Martin. This remix is licensed under Creative Commons Attribution 4.0 International License. The material has been adapted to fit the format and style of this course.