Further maths in one year?

So my school does this- basically we have almost twice as many lessons of maths in both years, so we get the content finished in the time required. Also some schools might do maths a level 1 year early. Hope this helps!

So the time you would've spent doing further maths in the first year, you spend doing more maths?

The sixth form college I'm applying to has an option for further maths which im considering, however, when i asked them for more information about it they told me that you do a level maths first year, and then further maths second year. And i was really confused because the only thing I know that you can do in one is an AS level exam, which i dont want to do, as i want an a level in both. Has anyone had any similar experiance like this and if so please explain a bit more about how it works like: is it some type of accelerated course? do you do exams for maths first or second year? And how do you fit a full a level in one year?
Any help will be useful, thank you.

I’m doing that rn in year 12.
Basically, you have twice the maths lessons which all are on A-Level maths. You’ll sit your a level maths exam with the year above (year 13’s) in year 12. I am sitting my a level maths in June but in year 12 as I do further maths and it works the same way. I think it’s better because you come out year 12 with an a level AND all the content is fresh in your mind for the a level exam!