#include<cstdio>

int main(){
	double x1,y1,x2,y2,x3,y3,xp,yp;
	int flug;
	double h;
	while(scanf("%lf %lf %lf %lf %lf %lf %lf %lf", &x1,&y1,&x2,&y2,&x3,&y3,&xp,&yp) + 1){
		x1 -= xp;
		x2 -= xp;
		x3 -= xp;
		y1 -= yp;
		y2 -= yp;
		y3 -= yp;
		flug = 0;
		if(x1 < 0.00001 || x1 > -0.00001){
			if(y1 > 0){
				if(y2 < 0 && y3 < 0){
					if(x2 * x3 < 0){
						flug = 1;
					}
				}
			}else{
				if(y2 > 0 && y3 > 0){
					if(x2 * x3 < 0){
						flug = 1;
					}
				}
			}
		}else{
			h = (y1 / x1 * x2 - y2)*(y1 / x1 * x3 - y3);
			if(x1 * x2 > 0 && y1 * y2 > 0){
				if(x3 * x1 < 0 && y3 * y1 < 0){
					if(h > 0){
						if(y2 / x2 * x1 - y3 < 0){
							flug = 1;
						}
					}
				}
			}
		}
		if(flug){
			printf("YES\n");
		}else{
			printf("NO\n");
		}
	}
	return 0;
}