Formula for accumulating values of numbers in varied location

Hi Guys,

I need help identifying the correct formula to use for this Excel Spreadsheet.

What formula can I use so that every time there is a "1" in the cell, Excel accumulates the corresponding "Total" value?

For example, In column "B1" the number "1" is present 6 times, and the corresponding "totals" are as follows "7+4+3+3+4+5" - How can i make it so Excel does this automatically. It is okay when you have a small amount of rows, but I have upwards of 400!

It is the TOTAL of the accumulated values that I am interested in (e.g 7+4+3+3+4+5 = 26)

I have attached a photo reference of my spreadsheet - Excel Help.png

I hope that I have explained my problem clearly here, any help would be greatly appreciated!

Thanks in advance!!

This works from what I can see so far through testing! Thank you so very much for your help, you've saved me a tonne of time and effort!!