First, we need to know the cause of the jam. If it is caused by improper personal use, such as littering toilet paper, then the responsibility should be borne by the individual. If it is caused by aging facilities or other reasons, then the responsibility should be borne by everyone.
Secondly, we can consider voting to share the cost. Everyone can vote to decide their share of the cost. If someone uses a large amount, then his share can be slightly higher; If someone uses less, then his share can be slightly lower.
In addition, fair random distribution can also be considered. Everyone can come up with an equal amount, and then draw lots to decide who will bear the cost.
Finally, we need to reach an understanding through communication and consultation. Everyone needs to abide by public health rules, use toilet facilities correctly, and maintain the sanitary environment of the dormitory to avoid similar situations from happening again.
In short, cost sharing needs to follow the principle of fairness and reasonableness, consider the interests and responsibilities of all parties, and take appropriate measures to solve the cost sharing problem.