B\u00ean c\u1ea1nh \u0111\u00f3 th\u00ec c\u00e1c c\u1eb7p s\u1ed1 n\u00e0y s\u1ebd \u0111\u01b0\u1ee3c ph\u00e2n lo\u1ea1i \u0111\u01b0\u1ee3c v\u00e0o \u0111\u1ec1 t\u1ed5ng ch\u1eb5n v\u00e0 \u0111\u1ec1 t\u1ed5ng l\u1ebb. M\u1ed7i lo\u1ea1i \u0111\u1ec1 t\u1ed5ng n\u00e0y ch\u00fang s\u1ebd c\u00f3 50 c\u1eb7p s\u1ed1, c\u1ee5 th\u1ec3:<\/p>\n
+ D\u00e0n \u0111\u1ec1 t\u1ed5ng ch\u1eb5n bao g\u1ed3m c\u00f3: 00, 02, 04, 06, 08, 20, 22, 24, 26, 28, 40, 42, 44, 46, 48, 60, 62, 64, 66, 68, 80, 82, 84, 86, 88, 11, 13, 15, 17, 19, 31, 33, 35, 37, 39, 51, 53, 55, 57, 59, 71, 73, 75, 77, 79, 91, 93, 95, 97, 99.<\/p>\n
+ D\u00e0n \u0111\u1ec1 t\u1ed5ng l\u1ebb bao g\u1ed3m c\u00e1c con s\u1ed1: 01, 03, 05, 07, 09, 21, 23, 25, 27, 29, 41, 43, 45, 47, 49, 61, 63, 65, 67, 69, 81, 83, 85, 87, 89, 10, 12, 14, 16, 18, 30, 32, 34, 36, 38, 50, 52, 54, 56, 58, 70, 72, 74, 76, 78, 90, 92, 94, 96, 98.<\/p>\n
V\u00ec s\u1ed1 l\u01b0\u1ee3ng d\u00e0n s\u1ed1 \u1edf ph\u00eda b\u00ean trong b\u1ed9 l\u00e0 t\u01b0\u01a1ng \u0111\u1ed1i nhi\u1ec1u. Ch\u00ednh v\u00ec v\u1eady cho n\u00ean c\u00e1ch soi c\u1ea7u ch\u1eb5n l\u1ebb mi\u1ec1n b\u1eafc n\u00e0y. \u0110\u01b0\u1ee3c c\u00e1c anh em ch\u01a1i \u0111\u1ec1 kh\u00e1 \u0111\u01b0\u1ee3c \u01b0a chu\u1ed9ng h\u01a1n h\u1eb3n.<\/p>\n