2.1.5 FriCAS

A grade: { 1, 2, 3, 4, 6, 26, 27 }

B grade: { 7, 8, 21, 22 }

C grade: { }

F grade: { 5, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 23, 24, 25, 28, 29, 30, 31 }