It's different. Tang Jiafeng 1800 is a question for students taking the postgraduate entrance examination in mathematics. According to official website of Tang Jiafeng 1800 product, the basic part of the number one is wider than the number two, such as infinite series, but the numbers together are not only important. Tang Jiafeng, male, Han nationality, 1966, born in Dongtai, Jiangsu Province, Ph.D., associate professor, Department of Mathematics, Nanjing University of Technology.