Create datatable based on cell selection of another datatable in a shiny app

datatable

#1

I have a simple shiny app with 2 datables.

#ui.r
navbarPage(
  "Application",
  tabPanel("General",
           sidebarLayout(

             sidebarPanel(
              ),
             mainPanel(
               DT::dataTableOutput("hot3"),
               br(),
               DT::dataTableOutput("hot5")
             )
           )))
#server.r
library(shiny)
library(DT)
server <- function(input, output,session) {

   DF= data.frame(Sel. = rep(TRUE,2),
               Label=paste("Test",as.integer(1:2)),
               Marg=rep("Marg1",2),
               Avail.=as.integer(rep.int(50,2)),
               Sel =as.integer(rep.int(50,2)),
               stringsAsFactors = FALSE)

  output$hot3 <-DT::renderDataTable(
    DF,
    selection=list(mode="single", target="cell")
  )
    output$hot5 <-DT::renderDataTable({
      DF = data.frame(
        Sel= rep(TRUE, as.numeric(input$hot3_cells_selected)),
        Id= 1:as.numeric(input$hot3_cells_selected),
        Label=paste("Item",as.integer(1:as.numeric(input$hot3_cells_selected))),
        Pf=as.integer(rep.int(0,as.numeric(input$hot3_cells_selected))),
        stringsAsFactors = FALSE)
      DF
    })


}

What I want to achieve is when I click on the "Avail" cell (50) to create a new data frame with 50 rpws which will be displayed in a new data table.
Screenshot_1
but I take as error

Error in rep: invalid 'times' argument