There are points on a plane. The coordinates of the -th point are .
Dadas wants to cover all the points with exactly four squares of equal size.
The sides of each square must be parallel to the coordinate axes. The squares may overlap. A point is considered covered if it lies inside or on the boundary of at least one square.
Let be the common side length of the four squares. Find the minimum possible such that every point is covered by at least one square.
The first line contains the number of points, .
Each of the next lines contains two integers , the coordinates of the -th point.
Print the minimum side length of four equal-sized squares that together cover all the points.
The input is given in the following format: