import java.util.*;
import java.lang.*;
import java.io.*;

class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner in = new Scanner(System.in);
		double a1 = in. nextDouble(), a2 = in. nextDouble();
		double b1 = in. nextDouble(), b2 = in. nextDouble();
		double c1 = in. nextDouble(),c2 = in. nextDouble();
		double x = in. nextDouble(), y = in. nextDouble(), f, g;
		f = (y - a2)*(b1 - a1) - (x - a1)*(b2 - a2);
		g = (c2 - a2)*(b1 - a1) - (c1 - a1)*(b2 - a2);
		if (f*g > 0) {
			f = (y - a2)*(c1 - a1) - (x - a1)*(c2 - a2);
			g = (b2 - a2)*(c1 - a1) - (b1 - a1)*(c2 - a2);
			if (f*g > 0) {
				f = (y - b2)*(c1 - b1) - (x - b1)*(c2 - b2);
				g = (a2 - b2)*(c1 - b1) - (a1 - b1)*(c2 - b2);
				if (f*g > 0)
					System.out.println("Yes\n");
				else
					System.out.println("No\n");
			}
			else
				System.out.println("No\n");
		}
		else
			System.out.println("No\n");
	}
}