Evaluate the line integral ∮F•dr by evaluating the surface integral in Stokes' Theorem with an appropriate choice of S. Assume
that C has a counterclockwise orientation when viewed from above. F = x^2 - y^2, z^2 - x^2, y^2 - z^2.C is the boundary of the square |x| ≤ 16, |y| ≤ 16 in the plane z = 0.