title: long long int initialization warnings
body: <p>2 Questions </p>
  
  <p>First, while</p>
  
  <pre><code>long long int num = 1000000000000;
  </code></pre>
  
  <p>works fine</p>
  
  <pre><code>long long int num = 4014109449;
  </code></pre>
  
  <p>gives</p>
  
  <pre><code>warning: this decimal constant is unsigned only in ISO C90 [enabled by default]
  </code></pre>
  
  <p>What does it mean ?</p>
  
  <p>Secondly</p>
  
  <pre><code>long long int num = 1000000*1000000;
  </code></pre>
  
  <p>gives an overflow warning 
  while</p>
  
  <pre><code>long long int num = 1000000000000;
  </code></pre>
  
  <p>is ok,even though they are same.How do i get rid of it? Multiplication gives a garbage value</p>