/*input
5
0 1
0 2
0 3
0 4
0 5
*/
#include <bits/stdc++.h>
#include<stdio.h>
using namespace std;
#define pii pair<long long,long long>
#define F(i,a,b) for(ll i = (ll)(a); i <= (ll)(b); i++)
#define RF(i,a,b) for(ll i = (ll)(a); i >= (ll)(b); i--)
#define PI 3.14159265
#define ll long long
#define ff first
#define ss second
#define pb(x) push_back(x)
#define mp(x,y) make_pair(x,y)
#define debug(x) cout << #x << " = " << x << endl
#define INF 1000000009
#define mod 1000000007
pii arr[100];
int main() 
{
	std::ios::sync_with_stdio(false);
	ll n;
	cin>>n;
	F(i,1,n)
	{
		ll x,y;
		cin>>x>>y;
		arr[i].ff=x;
		arr[i].ss=y;
	}
	bool f=1;
	F(i,1,n-1)
	{
		if(arr[i].ff != arr[i+1].ff)
			f=0;
	}
	bool g=1;
	F(i,1,n-1)
	{
		if(arr[i].ss != arr[i+1].ss)
			g=0;
	}
	if(f || g)
		cout<<"YES"<<endl;
	else
		cout<<"NO"<<endl;
	return 0;
}