Cheapest and "Smallest" way to cut 6.5v to 5v

It should be connected directly to a plug,
I can make it 5v I just need to buy a 220-5v adapter but I just have a 6.5v so you know, doesn't really matter that much.
Also, it may be a school project for an A.H :poop: professor and I really don't feel like ordering anything else for him lmao :joy: