//Ankur Jain	
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define sz(a) (int)(a.size())
#define all(c) (c).begin(),(c).end()
#define F first
#define S second
#define si(n) scanf("%d",&n)
#define sll(n) scanf("%lld",&n)
#define REP(i, begin, end) for (__typeof(end) i = (begin) - ((begin) > (end)); i != (end) - ((begin) > (end)); i += 1 - 2 * ((begin) > (end)))
#define MOD 1000000007
#define PI 3.14159265359
#define endl '\n'
typedef long long int ll;
typedef vector<int> vi;
typedef pair<int,int > ii;
typedef vector<ii> vii;
typedef vector< vi > vvi;
typedef pair<long long,long long> pll;
typedef vector<long long> vll;
typedef priority_queue < ll , vector < ll > , greater < ll > > minheap;
typedef priority_queue < ll , vector < ll > , less < ll > > maxheap;
ll gcd(ll m,ll n)
{
	if(n==0)
		return m;
	return gcd(n, m % n);
}
ll powmod(ll a,ll b)
{
	if(b==0)return 1;
	ll x=powmod(a,b/2);
	ll y=(x*x)%MOD;
	if(b%2)
		return (a*y)%MOD;
	return y%MOD;
}
//Template ends here
int main()
{
	int n;
	si(n);
	set< int > hor,ver;
	int x,y;
	REP(i,0,n)
	{
		si(x);si(y);
		hor.insert(y);
		ver.insert(x);
	}
	if(sz(hor)==1 || sz(ver)==1)
		printf("YES\n");
	else
		printf("NO\n");
	return 0;
}