1099R with RMD with Roth conversion

My 1099R has  RMD and ROTH Conversion from my IRA Account. 

Assuming my 1099R has both, say my RMD = $35,000 & my Roth Conversion is $15,000

Since I cannot directly get my RMD into my ROTH, I have to do a $15,000 conversion to ROTH.

Because Schwab need to do tax withholding, say, $2,000 was withheld and only $13,000 was transferred to my ROTH account.

So TT has a question:

What is the amount converted to ROTH IRA Account?  Is it $15,000 before tax withholding or $12,000 after? 

Thanks