#!/bin/python3

import math
import os
import random
import re
import sys

# Complete the solve function below.
def solve(board):
    a = board[0][0]
    for i in range(len(board)):
        for j in range(len(board[0])):
            if (i + j) % 2 == 0:
                if board[i][j] != a:
                    return 'No'
            else:
                if board[i][j] == a:
                    return 'No'
    return 'Yes'

if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    t = int(input().strip())

    for t_itr in range(t):
        n = int(input().strip())

        board = []

        for _ in range(n):
            board.append(list(map(int, input().rstrip().split())))

        result = solve(board)

        fptr.write(result + '\n')

    fptr.close()