#include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<cstdio>
using namespace std;
int main(){
    double xa,ya,xb,yb,xc,yc,xd,yd;
    while(cin>>xa>>ya){
        cin>>xb>>yb>>xc>>yc>>xd>>yd;
        double f=(xa-xb)*(xc-xd)+(ya-yb)*(yc-yd);
        if(f<=0.00001&&f>=-0.00001)
            cout<<"YES"<<endl;
        else
            cout<<"NO"<<endl;
    }
    return 0;
}