#!/bin/python3 import math import os import random import re import sys # Complete the solve function below. def solve(board): n = len(board) k = 0 pre = 1-board[0][0] for line in board: now = line[0] if(now == pre): return "No" pre = now nn = 1-line[0] for i in line: if(i == nn): return "No" else: nn = i 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()