Counting consecutive numbers in excel

Here is my problem:

I have a column of words, either "positive" or "negative" that corresponds to another column that let me know if a number was positive or negative. What I want to happen is to insert a new column to the right of this one to let me know how many days in a row it was positive or negative: It looks like this:

Colum A Column B
Positive 1
Positive 2
Negative 1
Positive 1
Positive 2
Positive 3
Positive 4
Negative 1
Positive 1
Negative 2
Negative 2


The issue I am having is trying to get a formula that would tell me how many days in a row it was positive or negative. I do not want to have to enter 1 2 1 1 2 3 4 ...etc. So I need a formula that I can put in column B and be able to copy down the entire column for any additional day I decide to add in there.

Thanks for you help!!!

Hello,

can you help me in a problem in excel?

In the range of A1:A18 have 18 numbers which can be both positive and negative (eg. 1.5, -1.3, 2, -2.3, etc...).
If all positive numbers using the product can calculate the product of these numbers.

=product(A1:A18) - results positive. This is OK.

If use an odd number of negative numbers then I get a negative results. This is OK.

If use an even number of negative numbers then i get a positive value. This is fine in math but i want to get a negative result in cell.

If any negative number in range A1:A18 then I would like to get the product negatively.

A1=2
A2=2
A3=2
A4=2

1) =product(A1:A4) = 16. OK

A1=-2
A2=2
A3=2
A4=2

2) =product(A1:A4) = -16. OK

A1=-2
A2=-2
A3=2
A4=2

3) =product(A1:A4) = 16. This is fine in Math but i need result -16.

Thanks all.