title: Python: invalid literal for int() with base 10
body: <p>I'm getting an <code>invalid literal for int() with base 10</code> where it seems as if the input stream is concatenating values generated in a loop.</p>
  
  <pre><code>def collectData():
      lst = makeCases()
      cases = int(input())
      for i in range(cases):
          size = int(input())
          case = []
          for j in range(size):
              value = int(input())
              case +=[value]
          insert(lst,case)
      return lst
  </code></pre>
  
  <p>That is the function generating the issue. The value and size variables are the problem as they seem to concatenate subsequent values before the conversion.</p>
  
  <p>The <code>makeCases()</code> function generates a tuple on the form <code>("Case",[])</code>.</p>
  
  <p>EDIT: The code works fine locally but won't work in the hackerrank IDE</p>