title: When using sys.stdin.read(), why I am not able to input from keyboard?
body: <p>My code is as follows:</p>
  
  <pre><code>def function(a, b):
      while a != 0 and b != 0:
        ...
  
      return x
  
  if __name__ == "__main__":
      input = sys.stdin.read()
      a, b = map(int, input.split())
      print(function(a, b))
  </code></pre>
  
  <p>When I try to run it, the program doesn't give me a chance to input.</p>
  
  <p>I get the following traceback message:</p>
  
  <pre><code>ValueError: not enough values to unpack (expected 2, got 0)
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/6j5Ye.png" alt="enter image description here"></p>
  
  <p>Can someone tell me the reason and how I can make input to test my program.</p>
  
  <p>Thanks a lot.</p>