#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 p;
    cin>>p;
    vector<pair<int,int> > points;
    int x,y;
    int flagh=0,flagv=0;
    for(int i=0;i<p;i++)
        {
        cin>>x>>y;
        points.push_back(make_pair(x,y));
        
    }
    int h=points[0].first,v=points[0].second;
    for(int i=1;i<p;i++)
        {
            if(points[i].first!=h)
                flagh=1;
            if(points[i].second!=v)
                flagv=1;
    }
    if(!flagh || !flagv ) cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}