Yu Jianchun, a native of Xinyang, Henan Province, once solved the century-old mathematical problem of Kammeyer's gram number as a courier. Later, after the discovery and support of Cai Tianxin, a professor of mathematics at Zhejiang University, it was highly recognized by experts. After becoming famous, Yu Jianchun maintained his awe of mathematics. Instead of pursuing fame and fortune, he became a data analyst in a company and engaged in his favorite mathematics industry.