//Author : Jatin Goyal
//codecracker4

#include<bits/stdc++.h>
using namespace std;
#define MOD 1000000007  //NA
#define N 11111
#define ll long long int
#define dt int
#define all(c) c.begin(), c.end()
#define dcl(a) memset(a,0,sizeof(a))
#define rep(i,a,b) for(dt i=a;i<=(dt)(b);i++)
#define tr(container, it) for(vector<dt> ::iterator it= container.begin(); it!=container.end(); it++)
#define trp(container, it) for(vector<pair<dt,dt> >::iterator it = container.begin(); it!=container.end(); it++)
#define cc1(a)cout<<#a<<": "<<a<<endl;
#define tra(container, it) for(typeof(container.begin()) it = container.begin(); it!=container.end(); it++)
#define cc2(a,b)cout<<#a<<": "<<a<<" , "<<#b<<": "<<b<< endl;
#define cc3(a,b,c)cout<<#a<<": "<<a<<" , "<<#b<<": "<<b<<" , "<<#c<<": "<<c<<endl;
#define cc4(a,b,c,d)cout<<#a<<": "<<a<<" , "<<#b<<": "<<b<<" , "<<#c<<": "<<c<<" , "<<#d<<": "<<d<<endl;
#define pr pair<dt,dt>  //NA
#define mp(a,b) make_pair(a,b)
#define pb push_back  //NA
#define gc getchar  //NA
#define F first
#define S second

int main()
{
	//freopen("##inp.cpp","r",stdin);
    //freopen("##out.cpp","w",stdout);
	//ios_base::sync_with_stdio(0);
	int t;
	t=1;
	rep(tes,1,t)
	{
	    int n,x[N],y[N],ctx=0,cty=0;
	    cin>>n;
	    rep(i,0,n-1) cin>>x[i]>>y[i];
	    rep(i,0,n-1)
	    {
	        if(x[i]==x[0]) ctx++;
	        if(y[i]==y[0]) cty++;
	    }
	    if((ctx==n)||(cty==n)) cout<<"YES";
	    else cout<<"NO";
	    cout<<endl;
	}
}