1099-R Tax Withheld

Hi, 

I have a question regarding a conversion from a IRA to a Roth IRA. I moved over $50k from my IRA to a Roth IRA and withheld $12k during this transaction. I received 2 1099-R forms, the first showing Box 1 12K, Box 2a 12K, 2b taxable amount not determined, Box 4 12K, Distribution Code 1 and the IRA/sep/Simple boxed checked. The other 1099-R showing Box 1 38K, Box 2a 38K, box 2b taxable amount not determined, Box 7- Code 2 and IRA/SEP/Simple checked. 

When entering the first 1099-R form in the question is Tell us if you moved the money through a rollover or conversion? Since this is the tax withholding amount $12k, not sure what to put ? I rolled over, I converted, i did a combination, or I didn't roll over or convert?