A loop ABCDEFA of straight edges has six corner points A(0,0,0), B(5,0,0), C(5,5,0), D(0,5,0), E(0,5,5) and F(0,0,5). The magnetic field in this region is B→=(3i^+4k^)T. The quantity of flux through the loop ABCDEFA (in Wb) is____.