#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <string>
#include <vector>
#include <utility>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cmath>
#include <cassert>
#define fi first
#define se second
#define sz(a) (int)(a).size()
using namespace std;

typedef long long ll;
typedef vector <int> vi;
typedef pair <int, int> ii;

int N;
int X[15], Y[15];

int main () {
	scanf ("%d", &N);
	for (int i = 0; i < N; i++) {
		scanf ("%d %d", &X[i], &Y[i]);
	}
	
	bool ok = true;
	for (int i = 1; i < N; i++) {
		if (X[i] != X[i - 1]) {
			ok = false;
			break;
		}
	}
	
	if (ok) {
		puts ("YES");
		return 0;
	}
	
	ok = true;
	for (int i = 1; i < N; i++) {
		if (Y[i] != Y[i - 1]) {
			ok = false;
			break;
		}
	}
	
	if (ok) {
		puts ("YES");
		return 0;
	}

	puts ("NO");
	return 0;
}