title: Only allowing Integer input in python 3.3.2
body: <p>Hi i am trying to make the program only accept the numbers 0, 4, 6, and 12, and not allow anything else to be inputted. So far i have been successful in only allowing certain integers to be entered, however i am having trouble with not allowing any letters to be entered. When a letter is entered, the entire program crashes. Please could you help me only allow integers to be entered? Thank you.</p>
  
  <p>My code is below:</p>
  
  <pre><code>from random import randint 
  def simul():
      dice = int(input("What sided dice would you like to roll? 4, 6 or 12? 0 to not roll:"))
      if dice != 4 and dice!=6 and dice!=12 and dice!=0:
          print('You must either enter 4, 6, or 12')
          simul()
      elif dice==0:
          exit()
      else:
          while dice !=0 and dice==4 or dice==6 or dice ==12 :
              print (randint(1,dice))
              dice = int(input("What sided dice would you like to roll? 4, 6 or 12? press 0 to stop."))
  simul()
  </code></pre>