Produce Certain Number of Lines based on Known Data in R

Question

I am wondering if there is an existing function in R that can produce a certain number of blank lines in R. I will give an example as below。

First, this is an example data frame:

exampleData <- data.frame(homeNB = c("ANDERLECHT CENTRUM - WAYEZ", "GROTE MARKT"), outTripNB = c(2, 3))

The table will look like this:

  homeNB                             outTripNB
1 ANDERLECHT CENTRUM - WAYEZ         2
2                GROTE MARKT         3

Ideally, I would like to have something like this:

  homeNB                             outTripNB     toBeAdded
1 ANDERLECHT CENTRUM - WAYEZ         2             NA
2 ANDERLECHT CENTRUM - WAYEZ         2             NA
3 GROTE MARKT                        3             NA
4 GROTE MARKT                        3             NA
5 GROTE MARKT                        3             NA

So as you can see, the number of newly added lines is equal to the number in the column outTripNB. As I have lots of NB in my data so it will be possible for me to add this manually. I am wondering if you can help me with this? Thanks very much for your help :)