while line = gets
  ary = line.split(" ").map(&:to_f)
  ab = [ary[2] - ary[0], ary[3] - ary[1]]
  cd = [ary[6] - ary[4], ary[7] - ary[5]]
  puts (ab[0] * cd[0] + ab[1] * cd[1] == 0) ? "YES" : "NO"
end