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


int main() {
    int n;
    cin >> n;
    int x[n];
    int y[n];
    for(int i=0;i<n;i++){
        cin >> x[i];
        cin >> y[i];
    }
    sort(x,x+n);
    if(x[0]!=x[n-1]){
        sort(y,y+n);
        if(y[0]!=y[n-1]){
            cout << "NO" <<"\n";
        }
        else{
            cout << "YES" <<"\n";
        }
    }
    else{
        cout << "YES" <<"\n";
    }
    return 0;
}