## Problem

Given a squared sized grid G of size N in which each cell has a lowercase letter. Denote the character in the i th row and in the j th column as G[i][j] .

You can perform one operation as many times as you like: Swap two column adjacent characters in the same row G[i][j] and G[i][j+1] for all valid i,j .

Is it possible to rearrange the grid such that the following condition is true?

In other words, is it possible to rearrange the grid such that every row and every column is lexicographically sorted?

**Note**:

**Input Format**

The first line begins with T , the number of testcases. In each testcase you will be given N . The following N lines contain N lowercase english alphabet each, describing the grid.

**Output Format**

Print T lines. On the i th line print i th testcase or

`YES`

if it is possible to rearrange the grid in the `NO`

otherwise.**Constraints**

**Sample Input**

`1`

5

ebacd

fghij

olmkn

trpqs

xywuv

**Sample Output**

`YES`

## Analysis

- Sort each row
- Then check each column to check whether numbers are in increasing order or not