title: While loop over a list?
body: <p>I have a list of numbers, and I want it so, after inputting 3 numbers, they will sum up, unless one of the numbers is 13, then the rest of the numbers will be invalid and not summed up.</p>
  
  <p>So if the list were to be <code>[1, 13, 2]</code> the end sum would be 1.</p>
  
  <pre><code>total = 0
  def lucky_sum():
      total = 0
      lucky_sum = []
      a = input("Input a number")
      b = input("Input a number")
      c = input("Input a number")
      lucky_sum.append(a)
      lucky_sum.append(b)
      lucky_sum.append(c)
  
  
  while **What do I place here??** != 13:
      total += **and here**
      if i== 13:
          break
  print total
  
  lucky_sum()
  </code></pre>