title: adding integer to dictionary (TypeError: 'int' object is not subscriptable)
body: <p>I am trying to add a number inputted by the user next to the chosen value in the dictionary. I need to do it like this so many users can add to the same dictionary adding to the count but I get this error message</p>
  
  <pre class="lang-py prettyprint-override"><code>
  inventory={'p': 0, 'd': 0, 'r': 0}
  
  let = str(input("""From this selection:
  1. p
  2. d
  3. r
  Which letter would you like to produce?: """))
  bottle_num = int(input("How Many numbers Would You Like?"))
  for let in inventory:
      inventory[let] + bottle_num
  print(inventory[let][0])
  
  </code></pre>
  
  <p><strong>produces output of</strong></p>
  
  <pre><code>From this selection:
  1. p
  2. d
  3. r
  Which letter would you like to produce?: r
  How Many numbers Would You Like?5
  Traceback (most recent call last):
    File "C:/Users/$$$$$$$$$$/add_to_dict.py", line 12, in &lt;module&gt;
      print(inventory[let][0])
  TypeError: 'int' object is not subscriptable
  </code></pre>
  
  <p>$ signs were added in </p>