2.1.3 Maple

A grade: { 2, 6, 7, 9, 19, 24, 27, 32, 34, 36, 37, 43, 48 }

B grade: { 1, 3, 4, 8, 40, 42, 44, 47, 49, 50 }

C grade: { 5, 12, 18, 28, 31, 33, 35, 38, 39, 46 }

F grade: { 10, 11, 13, 14, 15, 16, 17, 20, 21, 22, 23, 25, 26, 29, 30, 41, 45 }