Problem with colouring the entire row based on odd or even number in the first cell

Hello, Excel gurus!

I need help with conditional formatting. I wish Excel to colour the entire row green based on the condition that the number in the first cell of the row is odd. I have leafed through the forum answers here and have played with various formulas but the result that I get is weird no matter what I try. The latest example is this: Excel does colour some rows green but I have no idea how it chooses the rows to colour because they are neither odd nor even. I don't seem to understand what is happening there.

Could anyone help please?
Thanks in advance!
Agnese