#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
long double x[5], y[5];
int main() {
	for (int i = 0; i < 5; i++) {
		cin >> x[i] >> y[i];
	}
	for (int i = 0; i < 5; i++) {
		for (int j = i + 1; j < 5; j++) {
			for (int k = j + 1; k < 5; k++) {
				long double xi = x[i], yi = y[i];
				long double xj = x[j], yj = y[j];
				long double xk = x[k], yk = y[k];
				xi -= xk, yi -= yk;
				xj -= xk, yj -= yk;
				if (xi * yj == xj * yi) {
					cout << "NO" << endl;
					return 0;
				}
			}
		}
	}
	for (int i = 0; i < 5; i++) {
		for (int j = 0; j < 5; j++) {
			for (int k = 0; k < 5; k++) {
				for (int l = 0; l < 5; l++) {
					if (i != j && i != k && i != l && j != k && j != l && k != l) {
						long double xi = x[i], yi = y[i];
						long double xj = x[j], yj = y[j];
						long double xk = x[k], yk = y[k];
						long double xl = x[l], yl = y[l];
						long double m = 0.5 * (-yj * xk + yi * (-xj + xk) + xi * (yj - yk) + xj * yk);
						long double s = 1 / (2 * m) * (yi * xk - xi * yk + (yk - yi) * xl + (xi - xk) * yl);
						long double t = 1 / (2 * m) * (xi * yj - yi * xj + (yi - yj) * xl + (xj - xi) * yl);
						if (0 < s && s < 1 && 0 < t && t < 1 && 0 < 1 - s - t && 1 - s - t < 1) {
							cout << "NO" << endl;
							return 0;
						}
					}
				}
			}
		}
	}
	cout << "YES" << endl;
}