title: Remove last numbers in rows in R
body: <p>This is a fragment of my data.frame:</p>
  
  <pre><code>MC0_1_N.1   a   c
  MC0_1_N.2   d   b
  MC0_5_N.1   b   c
  MC0_5_N.2   c   d
  MC0_5_N.3   a   b
  MC0_5_N.4   e   f
  MC0_5_N.5   a   h
  MC0_5_N.6   k   m
  MC0_5_N.7   s   z
  MC0_5_N.8   o   p
  MC0_5_N.9   p   r
  MC0_5_N.10  r   t
  </code></pre>
  
  <p>Is there any way to remove the last numbers of rows (1,2,3,4...) which formed after creating data.frame?</p>