/*

     |\   |  `|` |``\  ```|` |   |  /```\  |``\
     | \  |   |  |__/     |  |___| |     | |__/
     |  \ |   |  |  \     |  |   | |     | |  \
    _|   \|  _|_ |   \ \__)  |   |  \___/  |   \
      	
*/

#include <bits/stdc++.h>

using namespace std;

int n;
set <int> X, Y;

int main (int argc, char const *argv[]) {
	scanf("%d", &n); while (n--) {
		int x, y;
		scanf("%d %d", &x, &y);
		X.insert(x), Y.insert(y);
	}

	if (X.size() == 1 or Y.size() == 1) printf("YES\n");
	else printf("NO\n");
	return 0;
}