As shown in the figure below, a cantilever beam undergoes a completely reversing transverse load of F = ±2kN. For the material, Sut = 770 MPa and Syt = 420 MPa. The endurance limit Se' = 0.5×Sut and the strength at N=103 is 0.83×Sut. The surface modification factor ka = 0.488, the size modification factor kb = 0.85 and all other modification factors are 1.0. If the cantilever beam should support the load F for 104 cycles, determine the cross sectional area. Apply the safety factor of 1.5.