#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<cctype>
#include<math.h>
#include<string>
#include<string.h>
#include<stack>
#include<queue>
#include<vector>
#include<utility>
#include<set>
#include<map>
#include<stdlib.h>
#include<iomanip>
#include<complex>
using namespace std;

#define ll long long
#define ld long double
#define INF 1e9
#define LINF (ll)INF*INF
#define MOD 1000000007
#define rep(i,n) for(int i=0;i<(n);i++)
#define loop(i,a,n) for(int i=a;i<(n);i++)
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)

#define int ll //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
#define double long double

typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int,int> pii;
typedef vector<pii> vp;

int gcd(int a, int b){
    if(b==0) return a;
    return gcd(b,a%b);
}
int lcm(int a, int b){
    return a/gcd(a,b)*b;
}

const double PI=acos(-1);
const double EPS=1e-15; //うまくいかなかったらゆるめる
typedef complex<double> P;
typedef vector<P> G;
#define shosu(x) fixed<<setprecision(x)
#define diff(P,i) (P[(i+1)%P.size()] - P[i])

struct L : public vector<P> {
  L(const P &a, const P &b) {
    push_back(a); push_back(b);
  }
  L(){;}
};
struct C {
  P c;double r;
  C(const P &c,double r):c(c),r(r){}
};

namespace std{//演算子の定義
  bool operator < (const P& a,const P& b) {
    return real(a)!= real(b) ? real(a) < real(b) : imag(a) < imag(b);
    //return imag(a) != imag(b) ? imag(a) < imag(b) : real(a) < real(b)
  }
  bool operator == (const P& a,const P& b) {
    return a.real()==b.real() && a.imag()==b.imag();
  }
}



double dot(P a,P b) {
  return real(conj(a)*b);
}

double cross(P a,P b) {
  return imag(conj(a)*b);
}


bool isorthogonal(const L &l, const L &m) { //2直線の直交判定
  return fabs(dot(l[0]-l[1], m[0]-m[1])) < EPS;
}


P inP(){
  double x,y;
//  scanf("%lf,%lf", &x, &y);
  cin >> x >> y;
  P p(x,y);
  return p;
}


L inL(){
  P p1 = inP();
  P p2 = inP();
  L l(p1,p2);
  return l;
}

signed main(void) {
    double a,b;
    while(cin >> a >> b){
        P p1(a,b);
        P p2 = inP();
        L l1(p1,p2);
        L l2 = inL();
        if(isorthogonal(l1,l2))cout << "YES" << endl;
        else cout << "NO" << endl;
    }

}

