https://www.dlsite.com/maniax/work/=/product_id/RJ01118352.html
Big breasts versions:
3-72: Higher resolution text version
73-142: Higher resolution textless version
143-212: Lower resolution text version
212-282: Lower resolution textless version
Small breasts versions:
283-352: Higher resolution text version
353-422: Higher resolution textless version
423-492: Lower resolution text version
493-562: Lower resolution textless version
There may be slight differences between the big and small breast versions in the story or at least how it's presented (aside from the obvious) but I'm not 100% sure and I can't read Japanese.