title: End an input scanf when user press enter
body: <p>for example i ask the user to enter two inputs, </p>
  
  <pre><code>int x,y;
  scanf("%d %d",&amp;x,&amp;y);
  </code></pre>
  
  <p>i need a case where if the user enter ONLY one input and then press Enter(\n)
  the program must say Missing number of input</p>
  
  <p>any suggestions?</p>