input: 
  def swap_variables(x: int, y: int) -> (int, int):
      """ Swaps the values of two variables and returns the swapped values.
      >>> swap_variables(5, 10)
      (10, 5)
      >>> swap_variables(0, 0)
      (0, 0)
      >>> swap_variables(-3, 7)
      (7, -3)
      """
  
output:     temp = x
      x = y
      y = temp
      return x, y