Warren Buffett -- HAHAHAHAHAHAHAH

... and with Duke losing to Mercer, it seems Warren Buffett -- and his 1 BILLION DOLLARS -- are safe.

Unless, of course, you picked Mercer.

But you didn't.

No one did.

Sucks to be Duke.

In case you didn't know ... Buffett was offering a $1 billion prize to anyone who submitted a PERFECT bracket through Yahoo and Quicken Loans.

After the first day, 83% of the people in the contest were eliminated. It's unlikely anyone survived after the Duke upset..

BONUS: Here's Mercer player Kevin Canevari celebrating the win by busting out the Nae Nae.