```{r sillhouette-plots, echo=FALSE, message=FALSE}
library(shiny)
library(cluster)
library(dplyr)

ui <- fluidPage(
  wellPanel(
    fluidRow(
      column(4, offset=4,
             numericInput("k", "Number of clusters", min = 2, max = 8, value = 3)
      ))),
  plotOutput("sillhouettes")
)

server <- function(input, output, session) {
  output$sillhouettes <- renderPlot({
    sill.model <- pam(mtcars[-1], k = input$k)
    plot(mtcars, which.plots = 2, main = paste0("Sillhouette plot for data, k = ", input$k))
  })
}

shinyApp(ui, server)
```