> For the complete documentation index, see [llms.txt](https://gitbook-88.gitbook.io/ctf-writeup/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gitbook-88.gitbook.io/ctf-writeup/2019/2019-ji-ke-da-tiao-zhan/buyflag.md).

# BuyFlag

cookie改成1，然后是弱类型比较以及数字绕过