Count Repeating SIGN Cells Only

I have a column that tells whether an adjacent cell is positive or negative. I'm trying to come up with a macro/formula that will tell me how long (# of rows going down) a negative or positive sign repeats before changing.

So it would go down the column and count the rows where the same sign repeats. Once the SIGN switches from + to - or - to + the number goes back to 0. Essentially counting the cells that move in one direction (+ or -).

For example. if A1 = +, A2 = +, A3 = +, A4 = +, A5 = -, A6 = + then it would count A1:A4 and output 4 in B4, meaning that the numbers have stayed negative for 4 rows. For A4:A5 nothing should appear as this sign change we don't want to record. Same for A5:A6. I don't know how to make a formula/macro to identify a repeating SIGN, and then dynamically count all those rows until the sign changes. Does this make sense? I've been beating my head against the desk trying to figure it out with no luck.