About the proton impact velocity at LHC?

This one might sound silly: I’ve read about the Large Hadron Collider and i was wondering: There we have two beams of protons (travelling at 99.99% of the speed of light) that collide head on. So talking about a perfect collision (max velocity and head on collision) isn’t the impact speed greater that the speed of light? Isn’t this impossible in our universe? Sorry again if the question sounds stupid…