How many college credits do I need for advanced enlistment?

I am a tier II candidate and I want to qualify for the Navy's advanced enlistment to E-3, which requires 48 credits. I need 15 credits just to qualify for enlistment. My question is do I just need the 48 credits for advanced enlistment or do I need 15 credits in addition to the 48 credits to make a total of 63 credits in order to qualify for advanced enlistment?