You are given a $9\times9$ grid board.
You have 40 "$1$"s and 41 "$0$"s. You can put these numbers wherever you want on the board.
After that, you will take the sum of the numbers in each row and column and as a result there will be $18$ sums at the end.
Is it possible to have 9 even sums and 9 odd sums at the end? If so, give an example.
what is the maximum number of even sums?