input: 
  def calculate_distance(x1: int, y1: int, x2: int, y2: int) -> float:
      """ Calculate the Euclidean distance between two points (x1, y1) and (x2, y2) on a 
      two-dimensional plane.
      >>> calculate_distance(3, 4, -9, -2)
      12.727922061357855
      """
  
output:     return ((x2 - x1) ** 2 + (y2 - y1) ** 2) ** 0.5