A long vertical wire carries an unknown current. Coaxial with the wire is a long, thin, cylindrical conducting surface that carries a current of 31.7 mA upward. The cylindrical surface has a radius of 3.0 mm. If the magnitude of the magnetic field at a point 5.28 mm from the wire is 1.11 ?T, what is the current (in A) in the wire? Take upward to be the positive direction, and give your answer the appropriate sign to indicate the direction of the current in the wire.