#include <stdio.h>

int main () {
	int n, i;
	scanf ("%d", &n);
	int x[n], y[n], xs = 1, ys = 1;
	for (i = 0; i < n; i ++) {
		scanf ("%d %d", &x[i], &y[i]);
	}
	for (i = 1; i < n; i ++) {
		if (x[i] != x[0]) {
			xs = 0;
			break;
		}
	}
	for (i = 1; i < n; i ++) {
		if (y[i] != y[0]) {
			ys = 0;
			break;
		}
	}
	if (xs == 1 || ys == 1) {
		printf ("YES\n");
	}
	else {
		printf ("NO\n");
	}
	return 0;
}