title: Trying to find minimum and maximum from user input using Python, the sentinal value keeps appearing as -99 in the minimum
body: <p>I was wondering how to fix my program which asks for user input on any number.</p>
  
  <p>To terminate the program, you input -99. Everything goes well as far as input goes, until I hit -99 to stop the program where it becomes the minimum. This is my code. The final answer for the minimum value cannot be -99.</p>
  
  <pre><code>s = -99
  n = 1
  minimum = None
  maximum = None
  print ("Enter a series of numbers")
  print ("Enter -99 to quit.")
  while n != s:
      n = float(input("Number: "))
      if minimum is None or n &lt; minimum:
          minimum = n
      if maximum is None or n &gt; maximum:
          maximum = n
      print ("The maximum is: ", maximum)
      print ("The minimum is: ", minimum)
  </code></pre>