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