input: 
  def calculate_sum_using_lambda(a: int, b: int) -> int:
      """Calculate the sum of two variables using a lambda function.
      
      >>> calculate_sum_using_lambda(3, 4)
      7
      >>> calculate_sum_using_lambda(10, 20)
      30
      """
      sum = lambda x, y: x + y
      return sum(a, b)
  
output:     sum = lambda x, y: x + y
      return sum(a, b)