r: 1
R: 2
f(x, y) = r^(2) - (sqrt(x^(2) + y^(2)) - R)^(2)
a = Surface(((R + (r * cos(v))) * cos(u)), ((R + (r * cos(v))) * sin(u)), (r * sin(v)), u, 0, (2 * π), v, 0, (2 * π))