You would scream like that too if you knew the things it's seen.
Submitter TurboJens explains this fix: The fill valve split in half and the floater does not cut off the water supply. The towel keeps the water inside and the wrench keeps it from overflowing.
Eastern European hostels are always an adventure.
As you can tell by the floor, it's already eroded the tiles. Maybe they need to go back to diapers.