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 main do
    [x, y, z] = li()
    cond do
      y <= z -> z-2
      x <= z -> z-1
      true -> z
    end
    |> IO.puts
  end
end