do2;read(5,*,end=1)a,b,c,d,e,f,g,h 1 p=atan2(b-f,a-e)-atan2(d-f,c-e) i=0>sin(p)*sin(p-atan2(b-h,a-g)+atan2(d-h,c-g)) 2 print'(i0)',i end