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