Missing Puzzle piece, black and white
<a href="//www.flickr.com/people/86399392@N00" class="extiw" title="flickruser:86399392@N00">Willi Heidelbach</a>
CC BY 2.0
<a href="//commons.wikimedia.org/wiki/Flickr" class="mw-redirect" title="Flickr">Flickr</a>: <a rel="nofollow" class="external text" href="https://www.flickr.com/photos/86399392@N00/109403306">Puzzle2</a>