#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;
    cin >> n;
    int x[n], y[n], f1=0, f2=0;
    
    for(int i=0; i<n; ++i)
        {
        cin >> x[i] >> y[i];
    }
    
    for(int i=1; i<n; ++i)
        {
        if(x[i]!=x[0])
            f1 = 1;
        
        if(y[i]!=y[0])
            f2 = 1;
    }
    
    if(f1 && f2)
        cout << "NO\n";
    
    else 
        cout << "YES\n";
    
    return 0;
}