defmodule Main do
  def main do
    IO.gets("")
    |> String.trim()
    |> String.split()
    |> process()
    |> IO.puts()
  end
  
  defp process([a, "+", b]), do:
    String.to_integer(a) + String.to_integer(b)
  defp process([a, "-", b]), do:
    String.to_integer(a) - String.to_integer(b)
  
end