#include <bits/stdc++.h>
using namespace std;
const int N = 11;
int n, x[N], y[N];

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n;
    for (int i = 1; i <= n; i++) cin >> x[i] >> y[i];
    int X = x[1], Y = y[1];
    //cout << X << ' ' << Y << endl;
    bool xx = 1, yy = 1;
    for (int i = 1; i <= n; i++) if (x[i] != X) xx = 0;
    for (int i = 1; i <= n; i++) if (y[i] != Y) yy = 0;

    if (xx || yy) cout << "YES" << endl;
    else cout << "NO" << endl;
}