The mole

A refinery removes sulfur dioxide from its exhaust gases using calcium carbonate, CaCO3). The balanced equation is:

$CaCO_3 + SO_2 \rightarrow CaSO_3 + CO_2$.

If the refinery emits 12 800 g of SO$_2$ per hour, what mass of CaCO$_3$ is needed each hour?
(Relative atomic masses: C = 12, O = 16, S = 32, Ca = 40)