Complex Contour Integrals

Hello,

I have been working on complex integration in my own time and have managed to solve a few, but these three seriously have me stumped. I was wondering if anyone would be willing to help me understand these problems.

a) where is the circle of radius 4 about the origin, traversed twice in the clockwise direction.

b) where proceeds around the boundary of the figure eight formed by two circles of radius 1 with centres 1 and −1 by starting at 0, going once counterclockwise around the right circle followed by going once counterclockwise around the left circle.

c) where is the circle of radius 2 about the origin.

I thank you all in advance! Your help is very much appreciated.