Something you will have plenty of time to assess once you get to second/3rd/4th year of your undergraduate degree
it's going to be very different to what you know now...
so much will change between now and then about how you view maths that it's not really worth thinking about yet.
EDIT... yeh i'm confused now - did you mean you already have a maths degree and are going there for a masters then maybe phd ... or you are about to start undergrad... as far as I can see they dont even have a straight maths Bsc/msci ... never mind one entirely on pure maths