#include <cstdio>
#include <cmath>
using namespace std;
typedef long long lint;

#define EPS 1e-15

struct point { double x, y; };

int main()
{
    point p[4];

    while (~scanf("%lf %lf", &p->x, &p->y)){
        for (int i = 1; i < 4; i++) scanf("%lf %lf", &p[i].x, &p[i].y);

        double p_side[3], side[3];
        for (int i = 0; i < 3; i++){
            p_side[i] = sqrt((p[i].x - p[3].x) * (p[i].x - p[3].x) + (p[i].y - p[3].y) * (p[i].y - p[3].y));
            side[i] = sqrt((p[(i + 1) % 3].x - p[i].x) * (p[(i + 1) % 3].x - p[i].x) + (p[(i + 1) % 3].y - p[i].y) * (p[(i + 1) % 3].y - p[i].y));
        }

        double p_s[3], s;
        for (int i = 0; i < 3; i++){
            double tmp = (p_side[i] + p_side[(i + 1) % 3] + side[i]) / 2;
            p_s[i] = sqrt(tmp * (tmp - p_side[i]) * (tmp - p_side[(i + 1) % 3]) * (tmp - side[i]));
        }
        double tmp = (side[0] + side[1] + side[2]) / 2;
        s = sqrt(tmp * (tmp - side[0]) * (tmp - side[1]) * (tmp - side[2]));

        //printf("%.20f\n", p_s[0] + p_s[1] + p_s[2] - s);
        if (p_s[0] + p_s[1] + p_s[2] - s <= EPS) puts("YES");
        else puts("NO");
    }

    return 0;
}