I'm facing what it looks like a relatively simple problem but yet hard for me to solve.
In beamer I have this footline in every slide as shown in this picture:

The missing thing is obviously the slides enumeration.
When I tried \setbeamertemplate{footline}[frame number], my footline was suddenly gone and replaced with page numbers as shown here:

So my point is, what do I need to do to include page enumeration inside the footline like this?

