Using zeTester. How-to.

First step:
Open zeTester and Sign Up in the system.


 

Then you can Sign In with your email and password.

Now click "Individual tasks" button in the central menu.

Then choose some task by clicking on it.

Now you can test your code. Be sure that your code's output matches the example's output.

Click submit button and you'll see your results in the block "Result".