#include<iostream>
#include<vector>
#include<algorithm>
#include<string.h>
#include<cstdio>
#include<math.h>
#include<cstdlib>
#include<map>
#include<utility>
#include<stack>
#include<fstream>

using namespace std;
#define ll long long int
vector <ll> v;
vector <ll> v1;
vector <ll> v2;
const ll inf=100000000000005;

#define cincout ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define me1(a,i) memset(a,i,sizeof(a))
#define me2(a,i,n,m) memset(a,i,n*m*sizeof(a[0][0]))
#define mp make_pair
#define pb push_back
#define sortv(v) sort(v.begin(),v.end())
#define printv(n,v) for(int i=0;i<n;i++)  {cout<<v[i]<<" ";}
#define vin(v,n,a) for(int i=0;i<n;i++)	{v.pb(a);cin>>v[i];}

int main()
	{
	cincout;
	int n;
	cin>>n;
	vector<pair<int,int> >po;
	int a,b;
	for(int i=0;i<n;i++)
		{
		cin>>a>>b;
		po.pb(mp(a,b));
		}
	bool done1=1,done2=1;
	for(int i=0;i<n-1;i++)
		{
		if(po[i].first!=po[i+1].first)
			done1=0;
		if(po[i].second!=po[i+1].second)
			done2=0;
		}
	if(done1==1 || done2==1)
		{
		cout<<"YES"<<endl;
		return 0;
		}
	cout<<"NO"<<endl;
  	return 0;
  	}