Based on data validation list value Formula

I have a data validation list on B3. My lists are 1st Qt., 2nd Qt., 3rd Qt., 4th Qt., 5th Qt., 6th Qt. in B3
and my answer is in B8


B8=IF (B3=”1st Qt.”, “2nd Qt.”, “”)
B8=IF (B3=”2nd Qt.”, “3nd Qt.”, “”)
B8=IF (B3=”3rd Qt.”, “4th Qt.”, “”)
B8=IF (B3=”4th Qt.”, “5th Qt.”, “”)
B8=IF (B3=”5th Qt.”, “6th Qt.”, “”)

I would like to get a one formula to B8. Maybe OR, AND

Please help.......

Thanks!