Do boys enter the classroom after girls in schools in your country?

I remember from my elementary school in Poland 20 years ago (I don't know how is it now), that some teachers, as part of teaching us "courtesy" and "savoir-vivre" required us to line up in two lines, with girls being let in first, then boys. This was particularly observed by female teachers. Msny boys did it out of habit even without being told to do so.

I wonder if such customs still exist in other countries, or have they died out?