input: def calculate_sum_using_lambda(a: int, b: int) -> callable:
      """Calculate the sum of two variables using a lambda function.
      >>> calculate_sum_using_lambda(3, 4)
      print(sum(3,4))
      """
      
      sum = lambda a, b : a + b
      return sum(a, b)
output:     
      sum = lambda a, b : a + b
      return sum
  