Mosquito Trap

The city of Osijek has a mosquito problem. An inventor from Benkovci proposed a trap shaped like a box. You leave out a piece of cheese or kajmak, wait for a mosquito to settle on it, then drop the box over the mosquito.

With some luck one box covers more than one mosquito. You have spotted $N$ mosquitoes on a table and you know every position exactly. Placing the sides of the box parallel to the sides of the table, what is the smallest possible area of a square box that covers every mosquito? A mosquito sitting on an edge of the box counts as covered.

The first line contains the integer $N$, the number of spotted mosquitoes ($2 \le N \le 20$).

Each of the next $N$ lines contains two space separated integers $X$ and $Y$, the coordinates of one mosquito ($1 \le X, Y \le 100$). The axes of the coordinate system are the sides of the table. At least two mosquitoes sit at different positions.

Print on one line the smallest area of a square box that covers every mosquito, measured in unit squares of that coordinate system.

In the first example a square whose opposite corners are $(3, 3)$ and $(7, 7)$ covers every mosquito.