What is the execution order of content scripts in Google Chrome extensions?

Question

JavaScript

It is required to embed the code on the page, which would be executed the very first before the execution of the rest of the scripts. I tried to insert my code immediately after the title tag using the content script, but alas: the code inserted in this way is by no means the first to be executed, running late.
Tell me how to execute the code on the page very first?