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

#define DEBUG(x)	cerr << #x << " = " << x << endl;
#define INPUT		freopen("Data.inp", "r", stdin);
#define OUTPUT		freopen("Data.out", "w", stdout);

typedef long long LL;
typedef pair<int, int> II;

int main() {
	#ifdef LOCAL
		INPUT;
		OUTPUT;
	#endif

	int n, x[100], y[100];
	cin >> n;
	for (int i = 0; i < n; ++i) cin >> x[i] >> y[i];

	if (*max_element(x, x + n) == *min_element(x, x + n) || *max_element(y, y + n) == *min_element(y, y + n))
		puts("YES");
	else
		puts("NO");

	return 0;
}