Enter the :ProconSet command to set up the site, contest, etc. that you challenge.
Then the plugin will create a new file with an appropriate name in the current directory.
If there is already a file with the same name, you can enter any name you like.
Write the code.
Enter the :ProconCheck command to make sure your program outputs the correct answer.
If your program outputs the correct answer, you'll get the AC. And of course, if it outputs the wrong answer, you'll get the WA.
Note: If the task accepts multiple answers, you may get the WA even if your program outputs the correct answer, because the plugin only compares it to the sample cases.
If you are confident that you'll get the AC, enter the :ProconSubmit to submit your code.