Computational Geometry

Time limit: 1 seconds

Memory limit: 512 megabytes

Problem Statement

MJ is an intelligent boy. He loves computational geometry so much that he can solve all the computational geometry in front of him.

However, Frank gives MJ a difficult computational geometry problem if it is calculated with the human brain. However, beyond Frank's expectation, MJ has developed his Programming skills this summer holiday.

Now, MJ tends to deal with the following question with the help of computer:

Frank offers MJ some integers $n$ nodes each located at point ($a_i$,$b_i$) and MJ can draw $n$ circles according to these points as the center of the circle.

He want MJ to find the minimum radius $r$ for all these $n$ circles so that all these circles these circles intersect indirectly or directly.

More precisely, draw $n$ circles each center located at point ($a_i$,$b_i$) and all their radius are $r$, and MJ can reach to any other start from the edge of a circle.

Specially, in order to check the answers you should print the smallest integer that is not less than $r$.

Input

The first line contains one integer $n(2 \le n \le 500)$.

In the following $n$ lines, each line contains two integers $a_i,b_i(-10^9\leq a_i,b_i \leq 10^9)$ denoting the center ($a_i,b_i$) of a circle.

Output

Print a single integer, denoting the minimum radius $\lceil r \rceil$.

3
-3 0
1 0
3 2

2