A chess board is composed by boxes black and white. The boxes are arranged by alternating the colors.
For this example, you need to replace black by 0 and white by 1, also the board size (columns and rows) is defined by the user.
columns = number
rows = number
$ your_script.rb 5 8
01010
10101
01010
10101
01010
10101
01010
10101