Let us describe the “cross” shape on a plane. For this, first, we choose a square on the plane. Note that each square can be viewed as the intersection of two infinite stripes on the plane which are orthogonal to each other. These stripes have the same width which is equal to the square side, and each edge of each stripe contains one of the square sides. The cross is the union of these two stripes with the square in the center. The size of a cross is the side of its center square. There are a few important points marked on the plane. Find the cross of minimum possible size which contains all these points inside or on its border.

The first line contains an integer n: the number of important points on the plane (4 ≤ n ≤ 50). Eachof the next n lines contains two integers  and  : the coordinates of i-th point ( ≤ 10 000). Allgiven points are distinct. It is guaranteed that the minimum possible size of a cross containing all thesepoints is at least 1. 

A decimal. You only need to output the width of the square.

5
0 0
0 10
10 0
10 10
10 20

4.472135954329

Your answer will right if your error no more than  .