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


int main() {
    int n;
    int f1=1,f2=1;
    cin >> n;
    int x[n], y[n];
    for(int i = 0; i < n; i++){
        cin >> x[i] >> y[i];
    }
    for(int i = 0; i < n; i++){
        if(x[i] != x[0]){
            f1 = 0;
            break;
        }
    }
    for(int i = 0; i < n; i++){
        if(y[i] != y[0]){
            f2 = 0;
            break;
        }
    }
    if((f1 + f2 == 1) || (f1 + f2 == 2)){
        cout << "YES" << endl;
    }
    else{
        cout << "NO" << endl;
    }
    return 0;
}