program yukiNo3005
    implicit none
    integer ax, ay, bx, by, cx, cy, dx, dy
    integer a, b, c, d, e
    
    read *, ax, ay, bx, by, cx, cy, dx, dy
    a = (bx - ax)**2 + (by - ay)**2
    b = (cx - ax)**2 + (cy - ay)**2
    c = (dx - ax)**2 + (dy - ay)**2
    d = (bx - ax)*(cx - ax) + (by - ay)*(cy - ay)
    e = (dx - ax)*(cx - ax) + (dy - ay)*(cy - ay)
    
    if       (((e**2 - c*b) * (b*(d-a)*(bx-ax) + a*(d-b)*(cx-ax))&
        &.eq.  (d**2 - a*b) * (b*(e-c)*(dx-ax) + c*(e-b)*(cx-ax)))&
        &.and.((e**2 - c*b) * (b*(d-a)*(by-ay) + a*(d-b)*(cy-ay))&
        &.eq.  (d**2 - a*b) * (b*(e-c)*(dy-ay) + c*(e-b)*(cy-ay)))) then
        print *, "YES"
    else
        print *, "NO"
    end if
end program yukiNo3005