// ----- Author Info -------
// Khaled Alam - Ninjo
// khaledalam.net@gmail.com
//--------------------------

#include <bits/stdc++.h>
using namespace std;

#define fi        first
#define se        second
#define pb        push_back
#define mp        make_pair
#define ll        long long
#define sz        size()
#define all(a)    (a).begin(), (a).end()
#define rep(i,z)  for(int i=0;i<z;i++)
#define ones      __builtin_popcount //__popcnt
#define iFile(a)  freopen(#a, "r", stdin)
#define oFile(a)  freopen(#a, "w", stdout)
#define i1(a)     ll a; scanf("%d",&a)
#define i2(a,b)   ll a,b; scanf("%d%d",&a,&b)
#define l1(a)     ll a; scanf("%I64d",&a)
#define l2(a,b)   ll a,b; scanf("%I64d%I64d",&a,&b)
#define ios       ios_base::sync_with_stdio(0)
#define tm        cerr<<"Time elapsed: "<<clock()<<" ms\n"

int main() {
	//iFile(input.txt);
	//oFile(output.txt);
	i1(n);
	int x[n], y[n];

	rep(i,n)
		cin >> x[i] >> y[i];

	if (count(x, x + n, x[0]) == n || count(y, y + n, y[0]) == n)
		cout << "YES";
	else
		cout << "NO";

}