//
// Created by Елена on 07.01.2020.
//
#include <iostream>
#include <vector>
#include <algorithm>
//#include <ostream>

using namespace std;

struct point {
    int x, y;

    point() {}

    point(int x, int y) : x(x), y(y) {}

    bool operator==(const point &rhs) const {
        return x == rhs.x && y == rhs.y;
    }
};

int rotate_det(const point &a, const point &b, const point &c) {
    return (b.x - a.x) * (c.y - a.y) - (c.x - a.x) * (b.y - a.y);
}

bool left_turn(const point &a, const point &b, const point &c) {
    return rotate_det(a, b, c) > 0;
}

int main() {
    int n, x0 ,y0;
    cin >> n >> x0 >> y0;
    vector<point> polygon;
    for (int i = 0; i < n; i++) {
        int x, y;
        cin >> x >> y;
        polygon.emplace_back(x, y);
    }
    if (left_turn(polygon[polygon.size() - 1 - 2], polygon[polygon.size() - 1 - 1], polygon[polygon.size() - 1])
    || left_turn(polygon[0], polygon[1], polygon[2])) {
        reverse(polygon.begin(), polygon.end());
    }

    point p(x0, y0);
    int count = 0;
    bool flag = false;
    for (size_t i = 0; i < polygon.size(); i++) {
        point l = polygon[i];
        point r;
        if(i == polygon.size() - 1) {
            r = polygon[0];
        } else {
            r = polygon[i + 1];
        }
        if (l.y > r.y) {
            swap(l, r);
        }
        if (r.y < p.y || l.y >= p.y) continue;
        int orient = rotate_det(l, r, p);
        if (orient == 0) {
            flag = true;
            break;
        }
        if (orient > 0) {
            count++;
        }
    }
    if(count % 2 ) {
        flag = true;
    }
    if(flag) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }
}
/*
 9 5 2
 0 2
 3 0
 2 2
 6 1
 5 6
 4 4
 3 5
 3 3
 1 3

 */