Please help me with a formula for the following:

I have a spreadsheet with Months as headings across the columns and products down the rows.

The range: A4:G50. ( Including headings ).

The cells are populated with sales per product for each month listed.

In cell E3, I would like to count how many products had Zero Sales across the six months.

I can do it by separately summing the columns for each product and counting the products with zero sales for the six months - but I have other info in those cells and I do not want to change the spreadsheet.

Thanks

JVN