# Object Clustering

Time Limit: 2000MS

Memory Limit: 131072K

## Description

We have N (N ≤ 10000) objects, and wish to classify them into several groups by judgement of their resemblance. To simply the model, each object has 2 indexes a and b (a, b ≤ 500). The resemblance of object i and object j is defined by dij = |ai - aj| + |bi - bj|, and then we say i is dij resemble to j. Now we want to find the minimum value of X, so that we can classify the N objects into K (K < N) groups, and in each group, one object is at most X resemble to another object in the same group, i.e, for every object i, if i is not the only member of the group, then there exists one object j (i ≠ j) in the same group that satisfies dijX

## Input

The first line contains two integers N and K. The following N lines each contain two integers a and b, which describe a object.

## Output

A single line contains the minimum X.

## Sample Input

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


## Sample Output

2

N/A