[Animation Nodes] Periodic Updates

I have a setup that I would like to refresh/update every couple of seconds or so. So let’s say I have a list of frame numbers: [73, 125, …]. The animation starts at frame 0. I would like to make a network that outputs an integer number which equals 0 for the frames 0 to 72, then changes to 1 at frame 73, then changes to 2 at frame 125, and so on.

When I try to implement this in AN, I always seem to end up with a network that loops back on itself, and is therefor not usable. Does anybody have any idea how I can implement this in AN? TIA!