#ifndef LOCAL
#include <bits/stdc++.h>
#define debug(...)
#endif

using namespace std;
#define int long long
#define cinv(v) for (auto &it:v) cin>>it;
#define coutv(v) for (auto &it:v) cout<< it<<' '; cout<<'\n';

template<class T> int sgn(T x) { return (x > 0) - (x < 0); }

template<class T> struct Point {
    typedef Point P;
    T x, y;

    explicit Point(T x = 0, T y = 0) : x(x), y(y) {
    }

    bool operator<(P p) const { return tie(x, y) < tie(p.x, p.y); }
    bool operator==(P p) const { return tie(x, y) == tie(p.x, p.y); }
    P operator+(P p) const { return P(x + p.x, y + p.y); }
    P operator-(P p) const { return P(x - p.x, y - p.y); }
    P operator*(T d) const { return P(x * d, y * d); }
    P operator/(T d) const { return P(x / d, y / d); }
    T dot(P p) const { return x * p.x + y * p.y; }
    T cross(P p) const { return x * p.y - y * p.x; }
    T cross(P a, P b) const { return (a - *this).cross(b - *this); }
    T dist2() const { return x * x + y * y; }
    double dist() const { return sqrt((double) dist2()); }
    // angle to x-axis in interval [-pi, pi]
    double angle() const { return atan2(y, x); }
    P unit() const { return *this / dist(); } // makes dist()=1
    P perp() const { return P(-y, x); } // rotates +90 degrees
    P normal() const { return perp().unit(); }
    // returns point rotated 'a' radians ccw around the origin
    P rotate(double a) const {
        return P(x * cos(a) - y * sin(a), x * sin(a) + y * cos(a));
    }

    friend ostream &operator<<(ostream &os, P p) {
        return os << "(" << p.x << "," << p.y << ")";
    }
};

void shelby() {
    int n;
    cin >> n;
    vector<Point<int> > v;
    for (int i = 0; i < n; ++i) {
        int x, y;
        cin >> x >> y;
        v.push_back(Point<int>(x, y));
    }
    v.push_back(v.front());
    Point<int> Nobita;
    cin >> Nobita.x >> Nobita.y;
    for (int i = 1; i < v.size(); ++i) {
        if (v[i - 1].cross(Nobita, v[i])) {
            cout << "YES\n";
            return;
        }
    }
    cout << "NO\n";
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    int t = 1;
    // cin >> t;
    for (int _ = 1; _ <= t; ++_) {
        // cout << "Case " << _ << ": ";
        shelby();
    }
}