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


int main() {
    int n; cin >> n;
    set<int> stx,sty;
    for (int i = 0; i < n; i++) {
        int x,y; cin >> x >> y;
        stx.insert(x);
        sty.insert(y);
    }
    if (stx.size() == 1 || sty.size() == 1) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }
    return 0;
}