#include<iostream>
#include<string>
using namespace std;
int main(){
	double ax,bx,cx,dx,ay,by,cy,dy;
	while(cin>>ax>>ay>>bx>>by>>cx>>cy>>dx>>dy){
		bool t=false;
		if((ay-by)/(ax-bx)==-(cx-dx)/(cy-dy))
			t=true;
		if((ax-bx)/(ay-by)==-(cy-dy)/(cx-dx))
			t=true;
		if(t==true)
			cout<<"YES"<<endl;
		if(t==false)
			cout<<"NO"<<endl;
	}
	return 0;
}