I have a Excel formula i need to adjust

I need to adjust the attached excel file's formula.

I need multiple Employee and Hours columns to contribute to the same Total Dollars.

How can i adjust this formula so that,

         B               C               D                E                F                G                H                I                  J                K                L                M                N
Employee | Hours | Employee | Hours | Employee | Hours | Employee | Hours | Employee | Hours | Employee | Hours | Total Dollars

So i need to calculate each employee hours (and some may be blank) then put that total in N.

          B               C               D                E                F                G                H                I                  J                K                L                M                N
chad           |    1.5    |    Dan      |     4.2    |    Eric       |     5.2    | Employee | Hours | Employee | Hours | Employee | Hours |    Total Dollars

i.e.     N (Total Dollars) = chad pay rate x 1.5  +  Dan pay rate x 4.2  +  Eric pay rate x 5.2
PayTable.xlsx