title: Excel: SUMIF an Undefined Range set by Blank Cells
body: <p>I'm trying to sum a range of cells with a changing range.</p>
  
  <pre><code>A   0
      0
      5
      0
  B   1
  C   2
      4
  </code></pre>
  
  <p>As in "A" should return 5, "B" 1, and "C" 6. Some research tells my that an OFFSET formula may work but I've got no luck.</p>