2025_2A. Manhattan Pairing
time limit per test
1.5 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

For a pair of points on the Cartesian plane $$$(x_1, y_1)$$$ and $$$(x_2, y_2)$$$, we define the Manhattan distance between them as $$$|x_1-x_2|+|y_1-y_2|$$$. For example, for the pair of points $$$(4, 1)$$$ and $$$(2, 7)$$$, the Manhattan distance between them is $$$|4-2|+|1-7| = 2+6 = 8$$$.

You are given $$$2 \cdot n$$$ points on the Cartesian plane, whose coordinates are integers. All $$$y$$$-coordinates of the given points are either $$$0$$$ or $$$1$$$.

Split the given points into $$$n$$$ pairs such that each of these points belongs to exactly one pair, and the maximum Manhattan distance between the points of one pair is minimized.

Input

The first line contains a single integer $$$n$$$ $$$(1 \le n \le 10^5)$$$.

In the following $$$2 \cdot n$$$ lines, each line contains two integers $$$x_i$$$ and $$$y_i$$$ $$$(0 \le x_i \le 10^9, 0 \le y_i \le 1)$$$ — the coordinates of the corresponding point.

Output

Output a single integer — the maximum Manhattan distance between the points of one pair in the optimal partition.

Scoring
  1. ($$$2$$$ points): $$$n = 1$$$;
  2. ($$$3$$$ points): $$$x_i = 0$$$ for $$$1 \le i \le 2\cdot n$$$;
  3. ($$$4$$$ points): $$$n \le 4$$$;
  4. ($$$11$$$ points): $$$n \le 10$$$;
  5. ($$$14$$$ points): $$$y_i = 0$$$ for $$$1 \le i \le 2\cdot n$$$;
  6. ($$$10$$$ points): $$$x_i \neq x_j$$$ for $$$1 \le i \lt j \le 2\cdot n$$$;
  7. ($$$29$$$ points): $$$n \le 1000$$$;
  8. ($$$27$$$ points): no additional restrictions.
Examples
Input
1
3 1
1 0
Output
3
Input
3
18 0
3 0
1 0
10 0
8 0
14 0
Output
4
Input
4
3 0
0 1
5 0
2 1
6 0
3 0
5 1
2 1
Output
2
Note

In the second example, the pairing $$$[(18, 0), (14, 0)]$$$, $$$[(3, 0), (1, 0)]$$$, and $$$[(8, 0), (10, 0)]$$$ is the only optimal partition. The Manhattan distances between the points of one pair in this partition are $$$4$$$, $$$2$$$, and $$$2$$$, respectively.

In the third example, the pairing $$$[(0, 1), (2, 1)]$$$, $$$[(2, 1), (3, 0)]$$$, $$$[(3, 0), (5, 0)]$$$, and $$$[(5, 1), (6, 0)]$$$ is an optimal partition. All Manhattan distances between the points of one pair in this partition are equal to $$$2$$$.

Illustration for the third example