//https://www.hackerrank.com/contests/101hack38/challenges/points-on-a-line
#include<bits/stdc++.h>
#define MOD 1000000007
#define S(x) scanf("%d",&x)
#define SLL(x) scanf("%lld",&x)
#define ll long long
#define pb push_back
#define mk make_pair
#define N 100005
using namespace std;
typedef pair<int,int> pii;
vector<pair<int,int> > v;
vector<int> g[N];
map<int,int> mp;
set<int> st;
int main()
{
	int n,f=0;
	S(n);
	for(int i=0;i<n;i++)
	{
		int x,y;
		S(x);S(y);
		v.pb(mk(x,y));
	}
	for(int i=1;i<n;i++)
	{
		if(v[i].first!=v[i-1].first)
		{
			f++;
			break;
		}
	}
	for(int i=1;i<n;i++)
	{
		if(v[i].second!=v[i-1].second)
		{
			f++;
			break;
		}
	}
	if(f<2)
		cout<<"YES"<<endl;
	else
		cout<<"NO"<<endl;
	return 0;
}