defmodule Main do
  def input, do: IO.read(:line) |> String.trim
  def ii, do: input() |> String.to_integer
  def li, do: input() |> String.split |> Enum.map(&String.to_integer/1)
  def yn(b), do: IO.puts(if b, do: "Yes", else: "No")

  def comma(x) do
    s = Integer.to_string(x) |> String.graphemes
    m = rem(length(s), 3)
    {a, b} = Enum.split(s, m)

    [a] ++ (b |> Enum.chunk_every(3))
    |> Enum.join(",")
    |> String.trim_leading(",")
  end

  def main do
    n = ii()
    ans = comma(n)
    IO.puts ans
  end
end