Given the task definition and input, reply with output. Given a travel related situation, and given a specific question about the situation, summarize the question into a title

I forgot to bring my padlock for this trip so my hostel in Taipei lent one to me until I buy one, which I keep forgetting to do.

The one they lent me is a generic "NO. 20" 4-barrel combination lock. There's no brand name in the instruction sheet. It has a feature where you can set or program the lock's combination.



I used the padlock fine about three times. But now I cannot get it to open just a couple of hours after last using it.

I did not forget the code. I set it to a year in the 20th century. I'm not sure the order of the last two digits but I've tried both many times, and I've even gone systematically through all 100 possibilities that begin with 1-9-?-?!

Is it a known problem with this kind of cheap padlock to "forget" or spontaneously change their combination?

(Yes I know I can just cut it off. But I'd feel like a bit of an idiot especially since the lock is not mine and is on loan. In fact the hostel must not own a pair of bolt cutters like I thought most do. They've asked a locksmith to come! I fear this may prove expensive, which is worse than just feeling like an idiot...)


Are cheap "programmable" combination padlocks known to change their own combinations?