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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n;
    scanf("%d", &n);
    vector <pair <int, int> > tab(n);
    for(int i = 0; i < n; i++)
        cin >> tab[i].first >> tab[i].second;
    bool a1 = true, a2 = true;
    for(int i = 0; i < n; i++) {
        if(tab[i].first != tab[0].first) a1 = false;
        if(tab[i].second != tab[0].second) a2 = false;
    }
    cout << (a1 || a2 ? "YES" : "NO");
}