2.1.2 Mathematica

A grade: { 2, 3, 5, 7, 9, 10, 11, 12, 15, 16, 17, 18, 22, 23, 24, 27, 28, 29, 30, 31, 32, 34, 35 }

B grade: { 8, 19, 20, 33 }

C grade: { 1, 4, 6, 13, 14, 21, 25, 26 }

F grade: { }