How does EXCEL automatically group names after entering them?

If column A is a place name and column B is a grouping, enter the following formula in B 1 and drop it down.

=IF(A 1= "place name 1", "group a", IF(A 1= "place name 2", "b," group b ",IF(A 1=" place name 3 ","c,

Note that there should be as many right parentheses as there are left parentheses in front.