1. A method for decoding a video, the method comprising: receiving a bitstream including information about a last coefficient location of a transformation block; obtaining a prefix bitstring of the last coefficient location among the information about the last coefficient location by performing context-based arithmetic decoding on the 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 a last coefficient location of a transformation block by using the inverse-binarized prefix and the inverse-binarized suffix, wherein a classification point between the prefix bitstring and the suffix bitstring which are related to the predetermined value is determined based on a size of the transformation block, and the inverse-binarized suffix is a remaining value of a symbol indicating the last coefficient location of the transformation block after the inverse-binarized prefix is excluded from the symbol.