#include <bits/stdc++.h>
using namespace std;

using db = double;
const db eps = 1e-9;

struct poi {
	db x, y;
	void r() { cin >> x >> y; }
	poi operator -(poi p) {
		return {x - p.x, y - p.y};
	}
	db cross(poi p) {
		return x * p.y - y * p.x;
	}
};

int main() {
	ios :: sync_with_stdio(false);
	poi a, b, c, d;
	while(cin >> a.x >> a.y) {
		b.r(); c.r(); d.r();
		db t = (b - a).cross(d - c);
		if(t > -eps && t < eps)
			cout << "YES\n";
		else
			cout << "NO\n";
	}
	return 0;
}