HMSRECT - Rectangle
You are given n points on the coordinate plane.
Write a program which calculates the largest possible area of a rectangle such that each of its vertices
is one of the given points. You may assume that such a rectangle exists.
The input is read from standard input. The ﬁrst line of input contains an integer n, the number of given points.
Each of the following n lines contains the coordinates of one point, two integers separated by a space.
The coordinates will be between −10^8 and 10^8.
No two points will be located at the same coordinates.
Output should be written to standard output. The ﬁrst and only line of output should contain a single
integer, the largest possible area of a rectangle.