def in_same_side?(ary_1, ary_2, ary_3, ary_p)
  a, b = ary_1
  c, d = ary_2
  i, k = ary_3
  p, q = ary_p
  alpha = (d - b)/(c - a)
  #ary_1, ary_2を通る直線 y = alpha * x + b - alpha * a
  if a == c
    laterality_ary_3 = i - a
    laterality_ary_p = p - a
  elsif b == d
    laterality_ary_3 = k - b
    laterality_ary_p = q - b
  else
    laterality_ary_3 = k - (alpha*i + b - alpha*a)
    laterality_ary_p = q - (alpha*p + b - alpha*a)
  end
  
  if laterality_ary_3 > 0 == laterality_ary_p > 0
    return true
  else
    return false
  end
end

while line = gets
  p = line.chomp.split.map(&:to_f).each_slice(2).to_a
  
  if in_same_side?(p[0], p[1], p[2], p[3]) && \
        in_same_side?(p[0], p[2], p[1], p[3]) && \
        in_same_side?(p[1], p[2], p[0], p[3])
    puts :YES
  else
    puts :NO
  end
end