Honestly, what an incredible french movie.
As far as you understand all the largo by watching it in french, this movie is definitely a must watch.
Starting by the story of a pityful family, to finish by a great regard about all the life pressure, it will give you goosebumps.
Now talking about the duration, it is just useful, it gives you the feel of the story and the family problems.
you wont regret it.