def checkOrthogonal(p)
  if p[2] - p[0] == 0
    return (p[5] == p[7])
  elsif p[6] - p[4] == 0
    return (p[1] == p[3])
  else
#  v1 = (p[3] - p[1]) / (p[2] - p[0])
#  v2 = (p[7] - p[5]) / (p[6] - p[4])
  return (p[3] - p[1]) * (p[7] - p[5]) == (p[2] - p[0]) * (p[4] - p[6])
  end
end

while input = $stdin.gets
  if checkOrthogonal(input.split(" ").map(&:to_f))
    puts "YES"
  else
    puts "NO"
  end
end