title: move cursor in insert mode from line2 head to line1 tail in vim
body: <pre><code>1234
  5678
  </code></pre>
  
  <p>In insert mode,if I want to move cursor from 5 to 4
  please tell me what should I do? 
  I dont want to change to normal mode and press <code>k$</code>
  Is there some way to do it in Insert mode?
  Something like using <code>&lt;-</code> key to move it.</p>
  
  <p>If I want to use <code>&lt;-</code> to do this ,what should I do?</p>