How do I get to cl on time?

I have to walk up to the 4th floor in my school every morning to get to science cl. Every morning when I start walking up the stairs, there are groups of these stupid kids who talk and take forever walking up. They're so inconsiderate that they cover the entire width of the staircase, and they hold up people behind them. There are way too many of them (about 15) to try to manuever through and they just ignore you when you tell them to move. They always make me 30 seconds late to cl. I told my teacher why I've been coming late and told her what homeroom they were in so she could write them up, but nothing has happened. They always start at a higher floor than me so I can never get in front of them. What should I do? There is no other path to get there. I'm sick of these idiots making me late all of the time to my AP science cl! They make me miss some of the notes when I'm late! I wish I could take them and push them down the stair case and break their necks!