A grade: { 1, 2, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 27, 28, 29, 30, 31, 36, 38 }
B grade: { 26, 34, 35, 66, 67, 68 }
C grade: { 12, 23, 42, 43, 44, 47, 50, 61, 62 }
F grade: { 3, 4, 32, 33, 37, 39, 40, 41, 45, 46, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 63, 64, 65, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96 }