import std.stdio;
import std.conv;
import std.algorithm;
import std.string;
import std.file;
import std.math;

int main() {
	string l;
	while((l = readln(), l.length)){
		l = l.split("\n")[0];
		
		float x1, y1, x2, y2, x3, y3, xp, yp;
		x1 = to!float(l.split[0]), y1 = to!float(l.split[1]);
		x2 = to!float(l.split[2]), y2 = to!float(l.split[3]);
		x3 = to!float(l.split[4]), y3 = to!float(l.split[5]);
		xp = to!float(l.split[6]), yp = to!float(l.split[7]);
		
		cfloat z1, z2, z3;
		z1 = (x1 - xp) + (y1 - yp) * 1.0i;
		z2 = (x2 - xp) + (y2 - yp) * 1.0i;
		z3 = (x3 - xp) + (y3 - yp) * 1.0i;
		
		cfloat r1, r2, r3;
		r1 = z2 / z1;
		r2 = z3 / z2;
		r3 = z1 / z3;
		
		if(r1.im > 0 && r2.im > 0 && r3.im > 0 || r1.im < 0 && r2.im < 0 && r3.im < 0) printf("YES\n");
		else printf("NO\n");
		}
	return 0;
	}