1. A method of decoding a video, the method comprising: obtaining a prefix bitstring of a last coefficient location of a transformation block by performing context-based arithmetic decoding on a received bitstream; when the prefix bitstring is greater than a predetermined value, obtaining, from the bitstream, a suffix bitstring according to a bypass mode; performing inverse binarization on the prefix bitstring according to a truncated binarization scheme to obtain an inverse-binarized prefix; performing inverse binarization on the suffix bitstring according to a fixed-length binarization scheme to obtain an inverse-binarized suffix; and reconstructing a symbol indicating the last coefficient location of the transformation block by using the inverse-binarized prefix and the inverse-binarized suffix, wherein a range of a value of the inverse-binarized prefix is determined based on a size of the transformation block and a range of a value of the inverse-binarized suffix is determined based on the value of the inverse-binarized prefix, wherein a value of the symbol indicating the last coefficient location of the transformation block is reconstructed by using the value of the inverse-binarized prefix and the value of the inverse-binarized suffix, and wherein the context-based arithmetic decoding is performed by using a context index determined based on a size of the transformation block.