Since all chess boards available in the market are boards, Alex decides to paint a customised board. Given the painted chess board, can you tell if it is painted correctly or not ? A chess board is considered valid if every adjacent cells are painted with different color. Two cells are considered adjacent if they share a boundary e.g.
Chess board in figure I is painted correctly though chess board in figure II is not.
Input Format
First line of input contains a single integer denoting the number of test cases.
First line of each test contains a single integer denoting the size of the board.
Next lines of each test case contains space separated integers.
If the integer in line is , it means that cell is painted in black color otherwise it is painted in white color and is represented with .
Constraints
Output Format
For each test case, Print Yes if the chess board is painted correctly, Print No otherwise in a new line.
Sample Input 0
2
2
0 0
0 0
2
0 1
1 0
Sample Output 0
No
Yes
Explanation 0
- In the first test case, adjacent cells are painted with same color making painted configuration invalid.
- In the second test case, every pair of adjacent cells is painted with different color making chess board configuration valid.