When i look at Chinese contestant in this year IOI , i am nearly depressed ... According to a blog on cf i read , they wrote that a Chinese contestant had reached LGM when he was in grade 9th LOL . Do you know their learning method to reach that level :((>?

What math level do i need for taking part in IOI ? and how to reach that level pls

I have trouble in solving problems on codeforce . Can u tell me how to train my mathematical skill pls;((