#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;
int 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++) {
				int xi = x[i], yi = y[i];
				int xj = x[j], yj = y[j];
				int xk = x[k], yk = y[k];
				xi -= xk, yi -= yk;
				xj -= xk, yj -= yk;
				if (xi * yj == xj * yi) {
					cout << "NO" << endl;
					return 0;
				}
			}
		}
	}
	cout << "YES" << endl;
}