#include <iostream>
#include <cstdio>
using namespace std;

int main(){
	double a[8], x, y;
	while(scanf("%lf", &a[0]) != EOF){
		for(int i = 1;i < 8;i++)scanf("%lf", &a[i]);
		//for(int i = 0;i < 8;i++)printf("%f ", a[i]);
		int f = 0;
		if((!(a[2]-a[0]) && !(a[7]-a[5])) ||
			(!(a[6]-a[4]) && !(a[3]-a[1])))f = 1;
		else {
			x = (a[3]-a[1])/(a[2]-a[0]);
			y = (a[7]-a[5])/(a[6]-a[4]);
		}
		//printf("%f %f\n", x, y);
		if(f || x * y == -1)cout << "YES" << endl;
		else cout << "NO" << endl;
	}
	return 0;
}