#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

bool is_vert(vector <int> &x) {
    for (int i = 1; i < int(x.size()); i ++) {
        if (x[i] - x[i-1] != 0) {
            return false;
        }
    }
    return true;
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    int n;
    cin >> n;
    vector <int> x(n), y(n);
    for (int i = 0; i < n; i ++) {
        cin >> x[i] >> y[i];
    }
    if (is_vert(x) || is_vert(y)) {
        cout << "YES\n";
    } else {
        cout << "NO\n";
    }
    return 0;
}