while s = gets do
  x1, y1, x2, y2, x3, y3, xp, yp = s.split.map(&:to_f)
  gx, gy = (x1 + x2 + x3) / 3, (y1 + y2 + y3) / 3 

  def c(x1, y1, x2, y2, x, y)
    (y2 - y1) * (x - x1) - (x2 - x1) * (y - y1) 
  end 

  r1 = c(x1, y1, x2, y2, gx, gy) * c(x1, y1, x2, y2, xp, yp) > 0 
  r2 = c(x2, y2, x3, y3, gx, gy) * c(x2, y2, x3, y3, xp, yp) > 0 
  r3 = c(x3, y3, x1, y1, gx, gy) * c(x3, y3, x1, y1, xp, yp) > 0 

  puts r1 && r2 && r3 ? 'YES' : 'NO'
end