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