A. Noodle Restauarant
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

There is a new noodle restaurant in town, in the shape of a square. There are $$$n$$$ tables on each side of the restaurant, totaling $$$n^2$$$ tables. For the annual inspection, the inspector wants to know what the product of the annual revenue is of all the tables on the 4 corners.

Input

The first input line will contain a single integer $$$n$$$ ($$$2 \leq n \leq 50$$$), representing the number of tables on each side of the restaurant. The following $$$n$$$ lines will each contain $$$n$$$ space-separated positive integers, representing the annual revenue of each table in the restaurant. All annual revenues will be between 1 dollar and 1000 dollars.

Output

Output the product of the annual revenue of all the tables on the 4 corners in dollars.

Examples
Input
2
7 3
5 1
Output
105
Input
3
1 3 4
3 1 4
5 7 2
Output
40