#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

std::vector<pair<int, int>> ps;

void Precalc()
{
}

void Solve()
{
	int n;
	cin >> n;
	ps.resize(n);
	for(auto &p: ps)
		cin >> p.first >> p.second;
	if(std::all_of(ps.begin(), ps.end(), [x=ps.front().first](auto &p) { return p.first==x; })||
		std::all_of(ps.begin(), ps.end(), [y=ps.front().second](auto &p) { return p.second==y; }))
	{
		printf("YES");
		return;
	}
	printf("NO");
}

int main()
{
	int t=1;
//	cin >> t;
	Precalc();
	for(int tc=1; tc<=t; ++tc)
	{
		Solve();
	}
}