Given a number n and a two-dimensional array of size nxn. Check if this 2D array is symmetrical about the main diagonal. Print the word “YES” if the two-dimensional array is symmetrical, and the word “NO” - otherwise.

Input
The first line contains a number n - the size of a two-dimensional array (n <= 10). Next come n lines of n numbers each - elements of a two-dimensional array.

Imprint
Print the word "YES" if the array is symmetric, or "NO" - otherwise