Here is the question...

Let F=xi-yj+zk and the pyramid be as shown below. Find $\displaystyle \iint\limits \,$$\displaystyle F\bullet dS$ as a surface integral over all five faces.

I really need some help with figuring out the surface integrals of each face. I think that the normal vectors of the two angled faces are $\displaystyle i+k$ and $\displaystyle j+k$, but I don't understand how to find the dS or the limits of integration since no real equation was given for the surface. I don't know whether I am just not seeing it or what, but can you guys help me out? Thanks in advance.