title: Search and replace exact pattern ignoring substring matches in vim
body: <p>There are 1000s of occurrences of <code>first</code> and <code>firstnum</code> in the file.</p>
  <p>I want to search for all occurrences of <code>first</code> and replace them with <code>firstnum</code>.</p>
  <p>However, <code>firstnum</code> occurrences shouldn't become <code>firstnumnum</code></p>
  <p>Is there any way to do it with <code>%s</code> ?</p>
  <p>Like</p>
  <pre><code>:%s/first/firstnum/gc
  </code></pre>
  <p>But I don't want to use <code>gc</code>, because in which case I will have to confirm for 1000s of matches of <code>first</code>.</p>