#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <limits.h>
#include <vector>
#include <stdlib.h>
#include <algorithm>
#include <memory.h>
#include <string.h>
#include <math.h>
#include <string>
#include <algorithm>
#include <functional>
#include <cassert>
#include <map>
#include <set>
#include <list>

using namespace std;
typedef long long lli;
typedef vector<int> vi;
typedef vector<lli> vli;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
typedef long double ld;

const int INF = 0x3f3f3f3f;
const lli LINF = 0x3f3f3f3f3f3f3f3f;

//#define _LOCAL_DEBUG_
#ifdef _LOCAL_DEBUG_
#define eprintf(...) fprintf(stderr,__VA_ARGS__)
#else
#define eprintf(...) 
#endif

const int MAX = 11;
int n;
pii p[MAX];


void clear() {
}

void solve() {
	for (int i = 0; i < n; i++) scanf("%d%d", &p[i].first, &p[i].second);

	int x = p[0].first, y = p[0].second;
	bool samex = true;
	for (int i = 0; i < n; i++) samex &= x == p[i].first;
	bool samey = true;
	for (int i = 0; i < n; i++) samey &= y == p[i].second;
	printf(samex || samey ? "YES\n" : "NO\n");
}

int main() {
#ifdef _LOCAL_VAN
	freopen("in.txt", "r", stdin);
#endif
	while (scanf("%d", &n) == 1) {
		clear();
		solve();
#ifndef _LOCAL_VAN
		return 0;
#endif
	}
	return 0;
}