#include <iostream>
#include <cstdio>
using namespace std;
#define rep2(x,from,to) for(int x = (from); x < (to); ++(x))
#define rep(x,to) rep2(x,0,to)

int main() {
	double d;
	double EPS = 1e-10;
	while(scanf("%lf", &d) != EOF) {
		double x[4], y[4];
		x[0] = d;
		rep(i,7) {
			if(i % 2) cin >> y[i / 2];
			else cin >> x[i / 2 + 1];
		}
		if(((x[1] - x[0]) * (y[1] - y[0]) + (x[3] - x[2]) * (y[3] - y[2])) > EPS) {
			cout << "YES" << endl;
		} else cout << "NO" << endl;
	}
	return 0;
}