The basic block named "CJK Unified Ideographs" (4E00–9FFF) contains 20,989 basic Chinese characters in the range U+4E00 through U+9FFC. The block not only includes characters used in the Chinese writing system but also kanji used in the Japanese writing system and hanja, whose use is diminishing in Korea. Many characters in this block are used in all three writing systems, while others are in only one or two of the three. Chinese characters are also used in Vietnam's Nôm script (now obsolete). The first 20,902 characters in the block are arranged according to the Kangxi Dictionary ordering of radicals. In this system the characters written with the fewest strokes are listed first. The remaining characters were added later, and so are not in radical order.