B"Fox Ciel has a board with n rows and n columns, there is one integer in each cell. It's known that n is an odd number, so let's introduce . Fox Ciel can do the following operation many times: she choose a sub-board with size x rows and x columns, then all numbers in it will be multiplied by -1. Return the maximal sum of numbers in the board that she can get by these operations. The first line contains an integer n, (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x8933, and n is an odd integer) -- the size of the board. Each of the next n lines contains n integers -- the numbers in the board. Each number doesn't exceed 1000 by its absolute value. Output a single integer: the maximal sum of numbers in the board that can be accomplished. In the first test, we can apply this operation twice: first on the top left 2 xe2 x80 x89 xc3 x97 xe2 x80 x892 sub-board, then on the bottom right 2 xe2 x80 x89 xc3 x97 xe2 x80 x892 sub-board. Then all numbers will become positive. "...