Given $n$ two-dimensional points in space, determine whether they lie on some vertical or horizontal line. If yes, print YES; otherwise, print NO.

Input Format

The first line contains a single positive integer, $n$, denoting the number of points.

Each line $\boldsymbol{i}$ of $n$ subsequent lines contain two space-separated integers detailing the respective values of $x_i$ and $y_i$ (i.e., the coordinates of the $i^{\mbox{th}}$ point).

Constraints

$2\leq n\leq10$
$-10\leq x_i,y_i\leq10$

Output Format

Print YES if all points lie on some horizontal or vertical line; otherwise, print NO.

Sample Input 0
5
0 1
0 2
0 3
0 4
0 5

Sample Output 0
YES

Explanation 0

All points lie on a vertical line.

Sample Input 1
5
0 1
0 2
1 3
0 4
0 5

Sample Output 1
NO

Explanation 1

The points do not all form a horizontal or vertical line.

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