2.1.2 Mathematica

A grade: { 1, 2, 3, 4, 6, 7, 10, 11, 14, 16, 18, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 38, 39, 40, 42, 43, 44, 45, 46, 48, 49, 50 }

B grade: { 9, 15, 17, 21, 41 }

C grade: { 5, 8, 12, 13, 37, 47 }

F grade: { }