Make good use of your time.
You want to focus. But people around you interrupt you all the time. What would you do?
Going to the office earlier—say, thirty minutes earlier—is one of the solutions. You can prioritize the things you need to do for the day, or actually do some of them without less interruption. That thirty minutes can be worth an hour or two in the middle of the day.
When it comes to productivity, how much you try to do doesn’t matter; quite often, how you make yourself concentrate matters.