#include<iostream>
using namespace std;

double X1, Y1, X2, Y2, X3, Y3, X4, Y4, X5, Y5;
double xp[1], yp[1];
double x[4], y[4];

int main() {
	while (cin >> X1 >> Y1 >> X2 >> Y2 >> X3 >> Y3 >> X4 >> Y4)
	{
		X5 = X3 - (Y4 - Y3);
		Y5 = Y3 + (X4 - X3);
		X4 = X5;
		Y4 = Y5;
		x[0] = X1; x[1] = X2; x[2] = X3; x[3] = X4;
		y[0] = Y1; y[1] = Y2; y[2] = Y3; y[3] = Y4;
		xp[0] = x[0] - x[1];
		yp[0] = y[0] - y[1];
		xp[1] = x[2] - x[3];
		yp[1] = y[2] - y[3];
		if (xp[0] == 0 && xp[1] == 0) { goto E; }
		if (yp[0] == 0 && yp[1] == 0) { goto E; }
		if (yp[0] == 0 && yp[1] != 0) { goto F; }
		if (yp[0] != 0 && yp[1] == 0) { goto F; }
		if ((xp[0] / yp[0]) == (xp[1] / yp[1])) { goto E; }
		goto F;
	E:; cout << "YES" << endl;
		goto G;
	F:; cout << "NO" << endl;
	G:;

	}
}