How do I sort choices in pickerInput alphabetically and force the choice "Other" to come at the end of the list?

Question

This is the code for my pickerInput in my shiny application. I want to sort all the choices alphabetically and force "Other" to come at the end of the list.

Here is my code and picture of pickerInput:

a <- c(unique(Data$Mode_group_new))


sidebarPanel(h3("Inputs for histogram"),
             pickerInput(inputId = "Mode_group_new",
                         label = "Select mode category",
                         choices = a,
                         multiple = T,
                         selected = a,
                         options = list(`actions-box`= TRUE)),