Division#426
A square cake of size n \times n (n \le 100) has (m \le 100) candles placed on it. Determine whether it is possible to divide the cake into two equal areas with a single straight cut so that all the candles are on one side. The candles are considered as points. The cut cannot pass through any candle.
The first line contains the number of tests. Each test consists of three lines. The first line of each test contains the integer — the length of the side of the square. The second line contains the integer — the number of candles on the cake. The third line contains the coordinates of the candles, separated by spaces: x_1, y_1, x_2, y_2, ..., x_m, y_m. All x_i and y_i are integers with 0 < x_i, y_i < n. The coordinates are given in a system with the origin at one corner of the square and the axes along the sides of the square. All coordinates are distinct and positive integers.
For each test, output a single line with YES if such a cut exists, or NO otherwise.
Example 1