Following Mao Zedong's death in 1976, Deng outmaneuvered the late chairman's chosen successor Hua Guofeng and became the "de facto" leader of China in December 1978. Inheriting a country beset with social conflict, disenchantment with the Communist Party and institutional disorder resulting from the chaotic policies of the Mao era, Deng started the "Boluan Fanzheng" program which brought the country back to order. From 1977 to early 1979, he resumed the National College Entrance Examination program that had been interrupted by the Cultural Revolution, initiated the historic Reform and Opening-up of China, and started a one-month Sino-Vietnamese War. In August 1980, he started China's political reforms by setting term limits for officials and proposing a systematic revision of China's third Constitution which was made under Hua Guofeng; the new Constitution embodied Chinese-style constitutionalism and was passed by the National People's Congress in December 1982, with most of its content still being effective as of today. In the 1980s, Deng supported the family planning policy to cope with China's overpopulation crisis, helped establish China's nine-year compulsory education, and launched the 863 Program for science and technology.