title: Python time limit exceeded
body: <p>i'm newbie in programming and my teacher asked the class to make a feel exercises in the judge system URI </p>
  
  <p>When I tried to do <a href="https://www.urionlinejudge.com.br/judge/pt/problems/view/2343" rel="nofollow noreferrer">this exercise</a> the URI system said  that my code exceeded the limit time, and ran in 2 seconds. My code was:</p>
  
  <pre><code>cont=0
  cont_register=int(input())
  coords=[]
  for i in range(cont_register):
      coords.append(input())
  for i in range(0, cont_register):
      if coords.count(coords[i])&gt;1:
          cont=1
          break
      else:
          cont=cont
  print(cont)
  </code></pre>
  
  <p>The output is always right, but I want to know if there are forms to optimize the running time, because the <code>cont_register</code> is a number between 2 and 500.000</p>