where is 981 come from?

[hsjkdjj]

hello, could you tell me what is this 981 mean? I'm confused.
copy from the code:
if student and int(timestep[0])<=981:
self.set_adapter('lora1')
self.enable_adapters()

copy from the paper:
"""
Specifically, we divided the ODE solution trajectory(xN , xN−1, ..., x1, x0) of the pre-trained model into two
sub-trajectories, using tκ as the boundary (we set N = 50 and κ = 37 by default).
"""

why it is different with paper? I mean 37/50*1000=740?