#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstring>
#include <cmath>
#include <fstream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };

ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;

ll det(ll x1, ll y1, ll x2, ll y2) {
	return x1 * y2 - x2 * y1;
}

int main() {
	vector<ll> x(5), y(5);
	for (int i = 0; i < 5; i++)
		cin >> x[i] >> y[i];
	for (int i = 0; i < 5; i++) {
		bool ok = false;
		for (int j = 0; j < 5; j++) {
			if (j == i) continue;
			ll dx = x[j] - x[i], dy = y[j] - y[i];
			vector<ll> d;
			for (int k = 0; k < 5; k++) {
				if (k == i || k == j) continue;
				d.push_back(det(dx, dy, x[k] - x[i], y[k] - y[i]));
			}
			sort(d.begin(), d.end());
			if (d[0] * d[2] > 0) ok = true;
		}
		if (!ok) {
			cout << "NO" << endl;
			return 0;
		}
	}
	cout << "YES" << endl;
}