SUMIFS with months, names, values Multiple Criteria Based on Months and Names

I'm trying to =sumifs( By different criteria but I'm having trouble.

Column A are dates 1/3/2016, 1/5/2016, 2/6/2016 and so on for hundreds of lines
Column B are names "jon" "bob" "bill"
Column C are values $500, $600, $700

I want to sum the values in "C" based on month of the year...THEN based on name.
So Jon, in January, totals $500
Bill in, February, totals $600

I can get the values for each of these separately but when I try the SUMIFS it gives me an error.

Any help is appreciated! Thank you!