Use the surface integral in Stoke's Theorem to calculate the circulation of the field F around the curve C in the indicated direction: F=x^2y^3i + j + zk, C: The intersection of the cylinder x^2+y^2=4 and the hemisphere x^2+y^2+z^2=16 , z greater or equal to 0, counter clockwise when viewed from above.

Can someone please help! I'm lost when it comes to Stokes!