1263: Laser

There are n enemies on a two-dimensional plane, and the position of the i-th enemy is (x_i,y_i)
You now have a laser weapon, which you can place on any grid (x, y)(x, y are real numbers), and the weapon fires a powerful laser that for any real number k, enemies at coordinates (x + k; y); (x; y + k); (x + k; y + k); (x + k; y - k) will be destroyed.
You are now wondering if it is possible to destroy all enemies with only one laser weapon.

The first line of input is a positive integer T(T <= 105) representing the number of data cases.
For each case, first line input a positive integer n to represent the position of the enemy.
Next n line, the i-th line inputs two positive integers xi, yi(-108 <= x_i , y_i  <= 108) represents the position of the i-th enemy.
The data guarantees that the sum of n for each test case does not exceed 500,000

For each cases, If all enemies can be destroyed with one laser weapon, output "YES otherwise output "NO"(not include quotation marks).

2
6
1 1
1 3
2 2
3 1
3 3
3 4
7
1 1
1 3
2 2
3 1
3 3
1 4
3 4

YES
NO