I believe that in primary school, when we were asked by the teacher what our future ideal was, many people would answer that they wanted to be a scientist. But as we grow older, we find how far we are from this ideal. Many people have long recognized the reality, forgotten their childhood ideals and faced real life. But there are also many people who have been sticking to their ideals and believe that as long as they work hard, they will succeed one day. Yu Jianchun, a Henan courier, has always adhered to his ideals. He solved a worldwide mathematical problem and was invited by a professor of Zhejiang University to give a lecture.

20 16 June, in a classroom of Zhejiang University, there was a heated discussion, and a group of doctoral professors were thinking about a difficult math problem. Just then, a man in plain clothes walked into the classroom, and the scholars who were thinking looked up at him in confusion, thinking that this man was in the wrong classroom. Just then, Cai Tianxin, a professor from Zhejiang University who came in behind the man, introduced him to everyone. It turns out that this man's name is Yu Jianchun, and this math seminar is specially held for him.

Yu Jianchun was born in an ordinary rural family in Xinyang, Henan. His childhood dream was to be a great mathematician. However, because he failed in the college entrance examination, he missed out on the university campus and finally went to a vocational high school to study animal husbandry. After graduation, Yu Jianchun has been engaged in various jobs, but even so, he never forgot his childhood dream and always regarded mathematics as his hobby. No matter where he goes, he will take some draft paper with him and calculate some mathematical formulas on it when he is free. In so many years of work, Yu Jianchun has not been idle. Every time he goes to a city, he will go to the local library to look up relevant information. Later, after finding a job as a courier, Yu Jianchun was able to enter the university campus and had the opportunity to meet some experts in mathematics.

Finally, through his own efforts, Yu Jianchun finally solved the problem of "Kammeyer number" which has puzzled the mathematics field for many years. However, because he was not sure about his solution, Yu Jianchun sent the manuscript to Cai Tianxin, a professor of mathematics at Zhejiang University, hoping that Professor Cai could verify his solution. However, Yu Jianchun never received a reply. Just when his faith sank into the sea, he received a reply from Professor Cai Tianxin. He decided to invite Yu Jianchun to Zhejiang University to attend a seminar, so that everyone could analyze whether his problem-solving ideas were correct.

Faced with so many math experts in the audience, Yu Jianchun was also very nervous, but he soon got into the state and successfully wrote his own ideas on the blackboard for everyone to see. When these experts asked him how he solved these problems so skillfully, Yu Jianchun replied that after years of calculation, these mathematical formulas had been deeply imprinted in his mind. This time, these experts in the audience heard his words, and their original doubts turned into approval, and the audience burst into warm applause.

A courier in Henan solved a worldwide mathematical problem, and a professor from Zhejiang University invited him to give a lecture. Although this kind of thing is incredible, Yu Jianchun did it. He didn't forget his childhood dream of becoming a mathematician, and he worked hard for this dream in the following decades, and finally succeeded. This spirit is something we should admire. I also hope that Yu Jianchun can make more achievements in the field of mathematics and really become an expert in mathematics.