#include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<cstdio>
using namespace std;
double dis(double xa,double ya,double xb,double yb){
    return sqrt((xa-xb)*(xa-xb)+(ya-yb)*(ya-yb));
}
int main(){
    double xa,ya,xb,yb,xc,yc,xd,yd;
    while(cin>>xa>>ya){
        cin>>xb>>yb>>xc>>yc>>xd>>yd;
        if((xa-xb)*(xc-xd)+(ya-yb)*(yc-yd)==0)
            cout<<"YES"<<endl;
        else
            cout<<"NO"<<endl;
    }
}