title: #Repeating a column in a data set
body: <p>I have a data set of this form:</p>
  
  <pre><code>ID   child1  child2  child3
  1     ADE      SOLA     BIMPE
  2    TUNDE     BYRA     FUNMY
  </code></pre>
  
  <p>And I want this output</p>
  
  <pre><code>1D   child
   1   ADE
   1   SOLA
   1   BIMPE
   2   TUNDE
  2    BYRA
  2    FUNMY  
  </code></pre>
  
  <p>Please how do I write a code in R to obtain that output     </p>