Excel wizard required!

Can anyone help - I have a big list of numbers (9000 numbers) they all have different attributes in about a few columns.
and I need to come up with a formula - that will count the number of fields that are the same in a row. so that I can look for the biggest run of numbers in a sequence.

i.e.

group no. Free?
1100 N
1101 Y
1102 Y
1103 N
1104 Y

The information I want is that there are 2 'Y's in a row.....
If I just sort by Ys for example it obviously takes the numbers out of sequence....
I was thinking.... of a formula =COUNTIF(IF cell =Y: B5, "=Y")

obviously the if cell bit I want to equal Y is to give the range? is doing my head in anyone know?

anyone help?