Trong b\u00e0i vi\u1ebft n\u00e0y ch\u00fang ta s\u1ebd c\u00f9ng nhau th\u1ea3o lu\u1eadn v\u1ec1 vi\u1ec7c g\u1eb7p con R\u1eafn trong m\u01a1. Tuy nhi\u00ean, m\u1ed7i gi\u1ea5c m\u01a1 l\u1ea1i mang \u0111\u1ebfn cho ch\u00fang ta nh\u1eefng \u0111i\u1ec1m b\u00e1o kh\u00e1c nhau c\u00f9ng s\u1ed1 \u0111\u00e1nh l\u00f4 \u0111\u1ec1 kh\u00e1c nhau.<\/p>\n