How to specify the number of odd and even numbers from a random generator in R?

I need to generate a random selection of 9 whole numbers from 1 to 40 with the following condition: the output must contain 5 even numbers and 4 odd numbers.

I have the following code to generate 9 random numbers:

x1<- sample(1:40, 9, replace=F)
> x1
  [1]  2 36  6 10 39 17 14 11 25

I now need to add the odd and even numbers condition in the equation. How can I do this?