It's simple... just like this...
1) I'll start with 1A
2) the next person have to continue the number but change the letter like this-> 1B
3) and so on....1C-1Z.. change the number...2A-2Z...and so on..got it?
I'll start....
1A
1) I'll start with 1A
2) the next person have to continue the number but change the letter like this-> 1B
3) and so on....1C-1Z.. change the number...2A-2Z...and so on..got it?
I'll start....
1A