The last string (the thinnest one) of one of my guitars is broken. How can I buy it?

I screwed up too much. It's broken these days 1 Fanta, 1 daddario, 2 Alice, 2 nobody. Yesterday, I installed another red cotton one. It's not broken. Probably because of the cold weather, the tension of the strings has become smaller. When tuning, slowly twist it bit by bit when it is close to the standard tone. If you are not sure, you can go to the next guitar tuning software, which is not bad.

Also, you bought a cotton tree for 5 yuan, and you were cheated by the music store. Generally, Alice marshmallow e 1 string is 1 yuan.

A set of fake Fanta is no more than 10 yuan, and a set of daddario is around 50 yuan.