24 cases

Two legs is not very simple,24 cases.We use a1b2 express leg1 put on sock and leg2 put shoe....All cases are:a1a2b1b2,a1b1a2b2,......,b2b1a2a1. a1b1b1b2 is ok,a2a1b1b2 is not ok for leg1.a1a2b2b1 is not ok for leg2.We cancel half for leg1 and cancel half for leg2.But for leg2 cancel half which half is canceled already.So,only 1/4 are left.8 legs only left 1/256.