#include <iostream>
#include <vector>
#include <iomanip>
#include <cmath>
using namespace std;
const double eps=0.000001;
struct point {
    double x,y;
};
struct Vector {
    long double x,y;
    Vector() = default;
    Vector (int x,int y): x(x),y(y) {}
    Vector operator * (int b) { return Vector(x*b,y*b); }
    Vector operator + (Vector v2) {return Vector(x+v2.x,y+v2.y); }
};
struct line {
    long double a,b,c;
    line (point p1, point p2) {
        a = p1.y - p2.y;
        b = p2.x - p1.x;
        c = -a*p2.x - p1.y*b;
    }
};
struct segment {
    point a,b;
    segment (point q, point w) {
        a=q;
        b=w;
    }
};
void printPoint (point p) {
    cout<<p.x<<" "<<p.y<<"\n";
}
void printVector (Vector p) {
    cout<<p.x<<" "<<p.y<<"\n";
}
double vectorLength(Vector a) {
    return a.x*a.x+a.y*a.y;
}
double pointDist (point a, point b) {
    return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
}

int dotproduct (Vector a, Vector b) {
    return a.x*b.x + a.y*b.y;
}
int crossproduct (Vector a, Vector b) {
    return a.x*b.y - a.y*b.x;
}
int main() {

    int a;
    cin>>a;

    vector <point> points(a+1);
    point C;
    cin >> C.x >> C.y;
    for (int i=0;i<a;i++) {cin >> points[i].x >> points[i].y;
    if (points[i].x == C.x && points[i].y == C.y)
    {
        cout<<"YES"; return 0;
    }
    }
    for (int i=0;i<a;i++) {
        points[i].x-= C.x;
        points[i].y-= C.y;

    }
    points[a] = points[0];
    int ans = 0;
    int weight[a];

    for (int i=0;i<a;i++) weight[i] = 0;
    for (int i=0;i<a;i++) {
      if (points[i].y > points[i+1].y) weight[i]++;
      if (points[i].y < points[i+1].y) weight[(i+1)%a]++;

    }
    for (int i=0;i<a;i++) {
      if (points[i].y == 0 && points[i].x >= 0) ans+= weight[i];
      if (C.x == points[i].x && C.y == points[i].y) {
          cout<<"YES"; return 0;

      }
    }

    for (int i=0;i<a;i++) {
      if (points[i].y * points[i+1].y < 0) {
          long double x1,x2,y1,y2;

          x1 = points[i].x;
          x2 = points[i+1].x;
          y1 = points[i].y;
          y2 = points[i+1].y;
          long double inter;
       inter= min(x1,x2) + abs(x2-x1) * max(y1,y2) / (abs(y1) + abs(y2));
       if (inter >= 0)  ans++;

      }
  }
  if (ans%2 == 1) cout<<"YES"; else cout<<"NO";

    return 0;
}