2.1.3 Maple

A grade: { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 16, 17, 18, 19 }

B grade: { 13, 14, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 }

C grade: { }

F grade: { }