I have weekly quizzes on Canvas in my classes, and I have a policy of dropping the lowest grade. At times, I also need to excuse a particular student from an assignment because of illness, etc. In those cases, I have been giving them a grade of EX. However, the algorithm to drop the lowest score seems to include the EX as a grade of 0, and drops that score. What I need to have it do is not count the quiz with the EX grade and also drop the lowest score from the student's other quizzes. How can I make this happen?