input: Write a python function to capture two numbers from the command line, calculate their sum, and return the result.
  assert capture_and_sum_numbers(3, 4) == 7
  assert capture_and_sum_numbers(10, 20) == 30
  assert capture_and_sum_numbers(-5, 5) == 0
output: def capture_and_sum_numbers(a, b):
      return a + b