combining an if and sum statement - possibly using countif

Can I please ask for assistance here.

I have an alphabetical sorted row of names (row A) and I want to know numerically how many times they appear and total in row B. (Running total or not)!

I believe the logic would be something like this IF(A1=A2) SUM B1+1 to B2 ELSE B2 =1 I can't see any excel statement that assists in accomplishing this.

Thank you in advance of anyone commenting on this problem.