Z 412 The Slopes of Line Segments

Xa,Ya,Xb,Yb=list(map(int,(input().split())))
Xp,Yp,Xq,Yq=list(map(int,(input().split())))
if Xb-Xa==0 or Xq-Xp==0:
    print("no")
else:
    slope1=float(Yb-Ya)//float(Xb-Xa)
    slope2=float(Yq-Yp)//float(Xq-Xp)

    if slope1 == slope2:
        print("yes")
    else:
        print("no")