#include <bits/stdc++.h>
#define r(i,n) for(int i=0;i<n;i++)
using namespace std;
#define EPS (1e-10)
#define equals(a,b) (fabs((a)-(b))<EPS)
//CCW??¨///////////////////////////////////
static const int COUNTER_CLOCKWISE = 1;
static const int CLOCKWISE = -1;
static const int ONLINE_BACK = 2;
static const int ONLINE_FRONT = -2;
static const int ON_SEGMENT = 0;
/////////////////////////////////////////
class Point{
  public:
  double x,y;
  Point(double x=0,double y=0):x(x),y(y){}
  Point operator + (Point p){return Point(x+p.x,y+p.y);}
  Point operator - (Point p){return Point(x-p.x,y-p.y);}
  Point operator * (double a){return Point(a*x,a*y);}
  Point operator / (double a){return Point(x/a,y/a);}

  bool operator < (const Point &p) const{
    return x!=p.x?x<p.x:y<p.y;
  }
  bool operator == (const Point &p) const{
    return fabs(x-p.x)<EPS&&fabs(y-p.y)<EPS;
  }
};
/*class Circle{
public:
  Point c;
  double r;
  Circle(Point c=Point(),double r=0.0):c(c),r(r){}
};*/
typedef Point vect;
struct seg{Point p1,p2;};
//????????´???
double norm(Point p){return p.x*p.x+p.y*p.y;}
//??¶??????
double abs(Point p){return sqrt(norm(p));}
//??????
double dot(Point a,Point b){
  return a.x*b.x+a.y*b.y;
}
//??????
double cross(Point a,Point b){
  return a.x*b.y-a.y*b.x;
}
//??´?????????
bool C90(seg s1,seg s2){
  return equals(dot(s1.p2-s1.p1,s2.p2-s2.p1),0.0);
}
bool C0(seg s1,seg s2){
  return equals(cross(s1.p2-s1.p1,s2.p2-s2.p1),0.0);
}
//?°???±
Point project(seg s,Point p){
  Point base = s.p2-s.p1;
  double r=dot(p-s.p1,base) / norm(base);
  return s.p1+base*r;
}
//????°?
Point reflection(seg s,Point p){
  return  p+(project(s,p)-p)*2.0;
}
//2???????????¢
double getDistancePP(Point a,Point b){
  return abs(a-b);
}
//??´??????????????¢(????°?)
double getDistanceLP(seg l,Point p){
  return abs(cross(l.p2-l.p1,p-l.p1)/abs(l.p2-l.p1));
}
//?????????????????¢
double getDistanceSP(seg s,Point p){
  if(dot(s.p2-s.p1,p-s.p1)<0.0)return abs(p-s.p1);
  if(dot(s.p1-s.p2,p-s.p2)<0.0)return abs(p-s.p2);
  return getDistanceLP(s,p);
}
//????¨?????????????????¨??????????
int CCW(Point p0,Point p1,Point p2){
  Point a=p1-p0;
  Point b=p2-p0;
  if(cross(a,b)>EPS)return COUNTER_CLOCKWISE;
  if(cross(a,b)<-EPS)return CLOCKWISE;
  if(dot(a,b)<-EPS)return ONLINE_BACK;
  if(norm(a)<norm(b))return ONLINE_FRONT;
  return ON_SEGMENT;
}
//??????????????????
bool intersect(Point p1,Point p2,Point p3,Point p4){
  return(CCW(p1,p2,p3)*CCW(p1,p2,p4)<=0&&CCW(p3,p4,p1)*CCW(p3,p4,p2)<=0);
}
bool intersect(seg s1,seg s2){
  return intersect(s1.p1,s1.p2,s2.p1,s2.p2);
}
//??????????????¢
double getDistance(seg s1,seg s2){
  if(intersect(s1,s2))return 0.0;
  return min(min(getDistanceSP(s1,s2.p1),getDistanceSP(s1,s2.p2)),
    min(getDistanceSP(s2,s1.p1),getDistanceSP(s2,s1.p2)));
}
//????????????
Point getCrossPoint(seg s1,seg s2){
  Point base=s2.p2-s2.p1;
  double d1=abs(cross(base,s1.p1-s2.p1));
  double d2=abs(cross(base,s1.p2-s2.p1));
  double t=d1/(d1+d2);
  return s1.p1+(s1.p2-s1.p1)*t;
}
//????´???°2D//////////////////////
typedef complex<double> comp;
typedef vector<comp> cvec;
//????´???????
double dot(comp a,comp b){return real(b*conj(a));}
//????´???????
double cross(comp a,comp b){return imag(b*conj(a));}
double Area(cvec &a){
  double b=0;int n=a.size();
  for(int i=0;i<n;i++)
    b+=cross(a[i],a[(i+1==n?0:i+1)]);
  return abs(b/2.0);
}
////how to use(exp)/////////////////////
//  double a,b; cvec t; cin>>n;       //
// while(n--){                        //
//    cin>>a>>b;                      //
//    t.push_back(comp(a,b));         //
//  }printf("%.11f\n",Area(t));       //
////////////////////////////////////////
main(){
  seg s,w;
  while(cin>>s.p1.x){
    cin>>s.p1.y>>s.p2.x>>s.p2.y;
    cin>>w.p1.x>>w.p1.y>>w.p2.x>>w.p2.y;
    if(C90(s,w))cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
  }
}

Measured memory_bytes: 3152