I lost my immigration receipt in Russia. How much will it cost to replace it?

It is recommended to fly back to China. Remember it's best to fly. Generally, airport staff are still relatively formal. Every airport has offices to deal with such problems. I lost it last year, too If you don't have any bad records, it's usually free. They will check whether you have a bad record from the microcomputer. If not, they will give you a new one for you to fill in and stamp! Remember to adopt when you are satisfied!