college dorm basement

hi, im just a regular college student and im looking for a cheap way to cover the walls of the basement in my house. im just making a estimate but i would say the rooms about 10ft x 25ft? its pretty moldy and a lot of the paint that is on flakes off if you just touch it. what im trying to do is make a little extra room for friends, so im not looking for anything expensive or anything thats going to take alot of time. i will only be in the house till the end of the semester but i might be getting this house again so i figure it will be worth it to fix up this room a little bit. whatever anyone thinks would be the cheapest way to cover the walls before painting, or even just something to cover the walls and forget about painting. thanks for your help!