#include <bits/stdc++.h>
using namespace std;

typedef int64_t ll;

#ifdef LOCAL
#include "debug.hpp"
#else
#define debug(...) 42
#endif

// Define a point
struct Point {
    double x, y;
    Point(double x, double y)
        : x{x}, y{y} {
    }
};

// Function to check if a point is on a line segment
bool onSegment(Point p, Point q, Point r) {
    return q.x <= max(p.x, r.x) && q.x >= min(p.x, r.x) &&
           q.y <= max(p.y, r.y) && q.y >= min(p.y, r.y);
}

// Function to find orientation of the ordered triplet (p, q, r)
// Returns:
// 0 -> p, q, and r are collinear
// 1 -> Clockwise
// 2 -> Counterclockwise
int orientation(Point p, Point q, Point r) {
    double val = (q.y - p.y) * (r.x - q.x) - (q.x - p.x) * (r.y - q.y);
    if (val == 0)
        return 0;             // Collinear
    return (val > 0) ? 1 : 2; // Clockwise or Counterclockwise
}

// Function to check if two line segments intersect
bool doIntersect(Point p1, Point q1, Point p2, Point q2) {
    int o1 = orientation(p1, q1, p2);
    int o2 = orientation(p1, q1, q2);
    int o3 = orientation(p2, q2, p1);
    int o4 = orientation(p2, q2, q1);

    // General case
    if (o1 != o2 && o3 != o4)
        return true;

    // Special cases: Check if points are collinear and on segment
    if (o1 == 0 && onSegment(p1, p2, q1))
        return true;
    if (o2 == 0 && onSegment(p1, q2, q1))
        return true;
    if (o3 == 0 && onSegment(p2, p1, q2))
        return true;
    if (o4 == 0 && onSegment(p2, q1, q2))
        return true;

    return false; // Otherwise, no intersection
}

// Function to check if a point is inside a polygon
bool isInsidePolygon(vector<Point> &polygon, Point p) {
    int n = polygon.size();
    if (n < 3)
        return false; // A polygon must have at least 3 vertices

    // Create a point for the ray (extending to the right)
    Point extreme = {1e9, p.y};

    // Count intersections of the ray with the polygon edges
    int count = 0, i = 0;
    do {
        int next = (i + 1) % n;

        // Check if the segment intersects with the ray
        if (doIntersect(polygon[i], polygon[next], p, extreme)) {
            // Check if the point is on the segment
            if (orientation(polygon[i], p, polygon[next]) == 0) {
                if (onSegment(polygon[i], p, polygon[next]))
                    return false;
            }
            count++;
        }
        i = next;
    } while (i != 0);

    // Point is inside if count is odd
    return count % 2 == 1;
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ll n;
    cin >> n;
    vector<Point> points;
    for (ll i = 1; i <= n; i++) {
        double x, y;
        cin >> x >> y;
        points.push_back(Point(x, y));
    }
    double x, y;
    cin >> x >> y;
    if (isInsidePolygon(points, Point(x, y))) {
        cout << "YES\n";
    } else {
        cout << "NO\n";
    }
}