It is year 2130. Colonizers from Earth landed on one of the planets of
the Alpha Centauri system. Their mission is to explore nearby planets
and stars. They
founded several spacecities, and developed advanced community.
Now, 14 years later,
they discovered that life is present in some of the nearby galaxies.
Also, all the galaxies on which life is found are located
so that they form a 3-dimensional rectangular array.
You may assume that there exists a rectangular parallelepiped divided
into cells with exactly 1 galaxy in each cell. The dimensions of the
parallelepiped are integer numbers M, N and D with 1 ≤ M,N,D ≤ 20,
and every cell is a cube with side 1.
The government of Alpha Centauri decided to build a space zoo.
The liveforms in different galaxies are different, so if a galaxy
becomes a part of a zoo, it gains some profit (for different
galaxies the profits are different). The main economist of the
settlement Mr. Ivanoff calculated the annual profits for each galaxy.
Current technology of building space constructions requires that
the space zoo must be a rectangular parallelepiped with sides
parallel to the sides of the parallelepiped that represents the
location of galaxies. Given the results of Ivanoff's calculations,
determine the highest profit or lowest loss that Alpha Centaurian
government can gain from building the zoo.

Given a rectangular parallelepiped divided into cells and the
numbers ascribed to the cells, determine the subparallelepiped
that has the largest sum of numbers in it. You may safely assume
that sum of numbers in each subparallelepiped is less than 32000.

Input
The first line of input contains 3 integes M, N, D, 1 ≤ M,N,D ≤ 20.
D blocks follow, each block consisting of M lines with N integers per
line that represent the profit values for corresponding galaxies.
Profits and losses (the latter represented as negatve profits)
are less than or equal to 500 in magnitude.

Output
Output should contain a single number — the highest profit (or the lower loss) possible.