#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iostream>
#include <iomanip>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <unordered_map>
#include <vector>
using namespace std;

int main(int argc, char const *argv[]){
	set<int> horizontal;
	set<int> vertical;
	int n; cin >> n;
	for (int i = 0; i < n; ++i)
	{
		int x, y; cin >> x >> y;
		horizontal.insert(y);
		vertical.insert(x);
	}

	horizontal.size() == 1 or vertical.size() == 1 ? cout << "YES" << endl : cout << "NO" << endl;
	return 0;
}