how to put default value in cells in a row of datagridview in vb.net?

how to put default value in cells in a row of datagridview in vb.net? I have a datagridview in vb.net and I want to put data in cells of a row, I want to put numbers in every cell in a row, from 1 to 31, randomly. any help would be awesome. thanks in advance a lot.