calculating an RMD

I feel like I should know this answer, but I'm not coming up with it.

Participant terminates employment at age 69 and rolls her balance to an IRA before the end of the year. After the first of the year, the employer deposits a discretionary contribution to the account. Participant will be 70 1/2 in the year of the deposit. I know her RMD must be the first money out, but with a zero balance at the end of the prior year, I don't remember how to calculate it.

$0/X = $0.00 where X is the MDIB factor.