title: Use of putStrLn to show result
body: <p>I am using the Idone.com site and wanted to run this code but do not know the syntax putStrLn to compile from stdin Use this code but strip error.</p>
  
  <pre><code>main = putStrLn (show (sumaCifras x))
  sumaCifras:: Int -&gt; Int
  sumaCifras x = div x 1000 + mod (div x 100) 10 + mod (div x 10) 10 + mod x 10
  </code></pre>