def checkOrthogonal(p)
  (p[6] - p[4]) * (p[2] - p[0]) + (p[7] - p[5]) * (p[3] - p[1]) == 0
end

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