title: Number of paths in a matrix
body: <p>A  <code>p x q</code> size matrix is given, and a matrix of size <code>a x b</code> is removed from top right corner. Find the total no. of paths from top left to bottom right, with only right and down movements allowed. No path should go into the removed matrix.</p>
  
  <p>eg-</p>
  
  <pre><code> _
  |_|_
  |_|_|
  </code></pre>
  
  <p>this is <code>(2x2)</code> matrix after removing <code>(1x1)</code> matrix from top right corner. no. of ways - <code>5</code>.</p>
  
  <p>I am able to find out the total number of paths, but the method I am thinking of eliminating the paths that go into the removed portion is very elementary and hence not efficient.</p>
  
  <p>So, are there any better algorithm for it ?</p>