IF command resetting after 3 consecutive negative results

Hi Everyone,

I'm trying to set up an IF command which would reset if the 3 previous calculations were a negative.

Here is how the data is set up

Columns A and B have max and min data.
Column C Shows the average of A and B.
Column D shows the cumulative result of Column C.

What I'm trying to do is after 3 negatives are shown in Column D, the next cell would reset to zero and the process start's over again.

I hope my questions is clear. Any help is appreciated.
Thanks