Fix the calculation of maximum_grade
Fix the calculation of maximum_grade

Coursemology/coursemology2,Coursemology/coursemology2,cysjonathan/coursemology2,Coursemology/coursemology2,cysjonathan/coursemology2,Coursemology/coursemology2,Coursemology/coursemology2,Coursemology/coursemology2,Coursemology/coursemology2,cysjonathan/coursemology2