#include <iostream>
#include <unordered_map>
#include <vector>
#include <algorithm>

using namespace std;

struct Point{
    int x, y;
};

Point* GetPoints(int n) {
    Point* p = new Point [n];
    for (int i = 0; i < n; ++i) {
        cin >> p[i].x >> p[i].y;
    }
    return p;
}

bool Check(const vector<int> v) {
    /*if (v.size() == 1) {
        return v[0] == 0;
    }*/
    for (int i = 0; i <= v.size() / 2; i++) {
        if (v[i] + v[v.size() - 1 - i] != 0) {
            return false;
        }
    }
    return true;
}

bool HasVerticalSymLine(int n, const Point p[]) {
    if (n == 0) {
        return true;
    }
    int sum_of_x = 0;
    for (int i = 0; i < n; i++) {
        sum_of_x += p[i].x * 2;
    }
    if (sum_of_x % n != 0) {
        return false;
    }
    int possible_axis = sum_of_x / n;
    unordered_map<int, vector<int>> y_to_x;
    for (int i = 0; i < n; i++) {
        y_to_x[p[i].y].push_back(2 * p[i].x - possible_axis);
    }
    for (auto& [y, x_vector] : y_to_x) {
        sort(x_vector.begin(), x_vector.end());
        if (!Check(x_vector)) {
            return false;
        }
    }
    return true;
}

int main() {

    //int n = 0;
    //cin >> n;
    //Point* p = GetPoints(n);
    {
        int n = 3;
        Point p[] = {
                {0, 0},
                {1, 1},
                {-1, 1}
        };
        if (HasVerticalSymLine(n, p)) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }
    }

    {
        int n = 4;
        Point p[] = {
                {1, 1},
                {2, 2},
                {1, 2},
                {2, 3}
        };
        if (HasVerticalSymLine(n, p)) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }
    }

    {
        int n = 3;
        Point p[] = {
                {0, 0},
                {0, 99},
                {0, 1}
        };
        if (HasVerticalSymLine(n, p)) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }
    }

    {
        int n = 3;
        Point p[] = {
                {0, 0},
                {0, 0},
                {1, 0   }
        };
        if (HasVerticalSymLine(n, p)) {
            cout << "YES" << endl;
        } else {
            cout << "NO" << endl;
        }
    }
    return 0;
}